One document matched: draft-cui-dhc-dhcpv6-yang-04.xml


<?xml version="1.0" encoding="US-ASCII"?>
<?xml-stylesheet type="text/xsl" href="rfc2629.xslt" ?>
<?rfc strict="yes" ?>
<?rfc toc="yes"?>
<?rfc tocdepth="4"?>
<?rfc symrefs="yes"?>
<?rfc sortrefs="yes" ?>
<?rfc compact="yes" ?>
<?rfc subcompact="no" ?>
<rfc category="std" docName="draft-cui-dhc-dhcpv6-yang-04" ipr="trust200902">
  <front>
    <title abbrev="YANG for DHCPv6">YANG Data Model for DHCPv6 Configuration</title>

  <author fullname="Yong Cui" initials="Y." surname="Cui">
    <organization>Tsinghua University</organization>
    <address>
    <postal>
      <street/>
      <city>Beijing</city>
      <code>100084</code>
      <country>P.R.China</country>
    </postal>
    <phone>+86-10-6260-3059</phone>
    <email>yong@csnet1.cs.tsinghua.edu.cn</email>
    </address>
  </author>
  
  <author fullname="Hao Wang" initials="H." surname="Wang">
    <organization>Tsinghua University</organization>
    <address>
    <postal>
      <street/>
      <city>Beijing</city>
      <code>100084</code>
      <country>P.R.China</country>
    </postal>
    <phone>+86-10-6278-5822</phone>
    <email>wangh13@mails.tsinghua.edu.cn</email>
    </address>
  </author>
  
  <author fullname="Linhui Sun" initials="L." surname="Sun">
    <organization>Tsinghua University</organization>
    <address>
    <postal>
      <street/>
      <city>Beijing</city>
      <code>100084</code>
      <country>P.R.China</country>
    </postal>
    <phone>+86-10-6278-5822</phone>
    <email>lh.sunlinh@gmail.com</email>
    </address>
  </author>
  
    <author fullname="Ted Lemon" initials="T" surname="Lemon">
      <organization abbrev="Nominum">Nominum, Inc.</organization>
      <address>
        <postal>
          <street>950 Charter St.</street>
          <city>Redwood City</city>
      <region>CA</region>
          <code>94043</code>
          <country>USA</country>
        </postal>
        <email>Ted.Lemon@nominum.com</email>
      </address>
    </author>
    
    <author fullname="Ian Farrer" initials="I.F" surname="Farrer">
      <organization>Deutsche Telekom AG</organization>
      <address>
        <postal>
          <street>CTO-ATI, Landgrabenweg 151</street>
          <city>Bonn</city>
          <region>NRW</region>
          <code>53227</code>
          <country>Germany</country>
        </postal>
        <email>ian.farrer@telekom.de</email>
      </address>
    </author>

    <date year="2015" />

    <workgroup>DHC Working Group</workgroup>

    <abstract>
      <t>There has no unified method to configure DHCPv6 server ,relay and 
      client itself, always pre-configured manually by operators.</t>
   
      <t>IETF netmod WG has developed a general data model for NETCONF 
      protocol, YANG data model <xref target="RFC6020"></xref>.</t>
   
      <t>This document defines a YANG data model for the configuration and
      management of DHCPv6 server, DHCPv6 relay and DHCPv6 client.  With
      this model, the operators can configure and manage the devices by
      using NETCONF.</t>
    </abstract> 

    <note title="Requirements Language">
      <t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
      "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
      document are to be interpreted as described in <xref
      target="RFC2119"></xref>.</t>
    </note>
  </front>

  <middle>
    <section anchor="introduction" title="Introduction">
      <t>This document defines a YANG data model for the configuration and
      management of DHCPv6 server, DHCPv6 relay and DHCPv6 client. With this 
      model, the operators can configure and manage the devices by using NETCONF.</t>

      <t>Model include three sub-modules:</t>

      <t><list style="symbols">

          <t>DHCPv6 server</t>

          <t>DHCPv6 relay</t>

          <t>DHCPv6 client</t>

        </list></t>
      <t>For DHCPv6 client configuration, it is worth noting that as 
        DHCPv6 itself a device configuration protocol, the intention of this
        document is not to replace client configuration of DHCPv6 options
        and parameters over the DHCPv6 protocol with the configuration of
        DHCPv6 options and parameters over NETCONF/YANG. The DHCPv6 client
        model is intended for the configuration of the DHCPv6 client
        function and also for obtaining read-only state data from the 
        client which has been learnt via the normal DHCPv6 message flow.
        This gives an operator a better method for managing DHCPv6
        clients and simplifies troubleshooting.</t>

      <section anchor="terminology" title="Terminology">
        <t>The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
        "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
        document are to be interpreted as described in <xref
        target="RFC2119"></xref>.</t>

        <t>The reader should be familiar with the terms defined in DHCPv6 
        <xref target="RFC3315"></xref> and relevant documents.</t>

        <t>DHCPv6 tree diagrams provide a concise representation of a YANG 
        module to help readers understand the module structure. The meaning if the 
        symbols in these diagrams is as follows:</t>

        <t><list style="symbols">
          <t>Brackets "[" and "]" enclose list keys.</t>
          <t>Braces "{" and "}" enclose feature content.</t>
          <t>Parentheses "(" and ")" enclose choice and case nodes, and 
          case nodes are also marked with a colon (":").</t>
          <t>Symbols after data node names: "?" means an optional node, 
          and "*" denotes a list and leaf-list.</t>
          <t>Abbreviations before data node names: "rw" means 
          configuration data (read-write), and "ro" means state data 
          (read-only).</t></list>
        </t>
      </section>

    </section>

    <section anchor="objectives" title="Objectives">
      <t>This document defines a YANG data model that can be used to configure
      and manage DHCPv6 server, DHCPv6 relay and DHCPv6 client.</t>

      <section anchor="dhcpv6server" title="DHCPv6 server">
        <t>DHCPv6 server parameters.</t>

      </section>

      <section anchor="dhcpv6relay" title="DHCPv6 relay">
        <t>DHCPv6 relay parameters.</t>
      </section>

      <section anchor="dhcpv6client" title="DHCPv6 client">
        <t>DHCPv6 client parameters.</t>
      </section>
    </section>

    <section anchor="tree-diagram" title="DHCPv6 Tree Diagrams">
      <section anchor="dhcpv6-server-tree" title="DHCPv6 Server Tree Diagrams">
        <figure align="center" anchor="structure" title="DHCPv6 Data Model Structure">
          <artwork><![CDATA[
+--rw dhcpv6
   +--rw server                                {dhcpv6-server}?
      +--rw serv-attributes
      |  +--rw name                            string
      |  +--rw duid                            duidtype                  
      |  +--rw enable                          boolean
      |  +--rw ipv6-address                    inet:ipv6-address
      |  +--rw description?                    string
      |  +--rw pd-function                     boolean  
      |  +--rw stateless-service               boolean
      |  +--rw rapid-commit                    boolean
      |  +--rw store-client-link-layer?        boolean
      |  +--rw vendor-info
      |     +--rw ent-num                      uint32
      |     +--rw data*                        string
      +--rw option-sets
      |  +--rw option-set* [option-set-id]
      |     +--rw option-set-id                uint8
      |     +--rw new-option* [option-code]
      |     |  +--rw option-code               uint16
      |     |  +--rw option-name               string
      |     |  +--rw option-description        string
      |     |  +--rw option-reference?         string
      |     |  +--rw option-value              string
      |     +--rw user-class-value?            string
      |     +--rw enterprise-number?           uint32
      |     +--rw store-client-link-layer?     boolean
      |     +--rw preference-option
      |     |  +--rw enable                    boolean
      |     |  +--rw preference-value          uint8
      |     +--rw sip-server-option
      |     |  +--rw enable                    boolean
      |     |  +--rw sip-server* [sip-serv-id]
      |     |     +--rw sip-serv-id            uint8
      |     |     +--rw sip-serv-domain-name   string
      |     |     +--rw sip-serv-addr          inet:ipv6-address
      |     +--rw dns-config-option
      |     |  +--rw enable                    boolean
      |     |  +--rw dns-server* [dns-serv-id]
      |     |  |  +--rw dns-serv-id            uint8
      |     |  |  +--rw dns-serv-addr          inet:ipv6-address
      |     |  +--rw domain-search-list        string
      |     +--rw nis-config-option
      |     |  +--rw enable                    boolean
      |     |  +--rw nis-server* [nis-serv-id]
      |     |     +--rw nis-serv-id            uint8
      |     |     +--rw nis-serv-addr          inet:ipv6-address
      |     +--rw nis-plus-config-option
      |     |  +--rw enable                    boolean
      |     |  +--rw nis-plus-server* [nis-plus-serv-id]
      |     |     +--rw nis-plus-serv-id       uint8
      |     |     +--rw nis-plus-serv-addr     inet:ipv6-address
      |     +--rw info-refresh-time-option
      |     |  +--rw enable                    boolean
      |     |  +--rw info-refresh-time         yang:timeticks
      |     +--rw cli-fqdn-option
      |     |  +--rw enable                    boolean
      |     |  +--rw server-initiate-update    boolean
      |     |  +--rw client-initiate-update    boolean
      |     |  +--rw modify-name-from-cli      boolean
      |     +--rw timezone-option
      |     |  +--rw enable                    boolean
      |     |  +--rw tz-posix                  string
      |     |  +--rw tz-database               string
      |     +--rw ntp-server-option
      |     |  +--rw enable                    boolean
      |     |  +--rw ntp-server* [ntp-serv-id]
      |     |     +--rw ntp-serv-id            uint8
      |     |     +--rw ntp-serv-addr          inet:ipv6-address
      |     |     +--rw ntp-serv-mul-addr      inet:ipv6-address
      |     |     +--rw ntp-serv-fqdn          string
      |     +--rw sntp-server-option
      |     |  +--rw enable                    boolean
      |     |  +--rw sntp-server* [sntp-serv-id]
      |     |     +--rw sntp-serv-id           uint8
      |     |     +--rw sntp-serv-addr         inet:ipv6-address
      |     +--rw network-boot-option
      |     |  +--rw enable                    boolean
      |     |  +--rw boot-file* [boot-file-id]
      |     |     +--rw boot-file-id           uint8
      |     |     +--rw suitable-arch-type*    uint16
      |     |     +--rw suitable-net-if*       uint32
      |     |     +--rw boot-file-url          string
      |     |     +--rw boot-file-paras* [para-id]
      |     |        +--rw para-id             uint8
      |     |        +--rw parameter           string
      |     +--rw dslite-option
      |     |  +--rw enable                    boolean
      |     |  +--rw dslite-aftr-name          string
      |     +--rw kerberos-option
      |     |  +--rw enable                    boolean
      |     |  +--rw default-realm-name        string
      |     |  +--rw kdc-info* [kdc-id]
      |     |     +--rw kdc-id                 uint8
      |     |     +--rw priority               uint16
      |     |     +--rw weight                 uint16
      |     |     +--rw transport-type         uint8
      |     |     +--rw port-number            uint16
      |     |     +--rw kdc-ipv6-addr          inet:ipv6-address
      |     |     +--rw realm-name             string
      |     +--rw addr-selection-option
      |     |  +--rw enable                    boolean
      |     |  +--rw a-bit-set                 boolean
      |     |  +--rw p-bit-set                 boolean
      |     |  +--rw policy-table* [policy-id]
      |     |     +--rw policy-id              uint8
      |     |     +--rw label                  uint8
      |     |     +--rw precedence             uint8
      |     |     +--rw prefix-len             uint8
      |     |     +--rw prefix                 inet:ipv6-prefix
      |     +--rw sol-max-rt-option
      |     |  +--rw enable                    boolean
      |     |  +--rw sol-max-rt-value          yang:timeticks
      |     +--rw inf-max-rt-option
      |     |  +--rw enable                    boolean
      |     |  +--rw inf-max-rt-value          yang:timeticks
      |     +--rw pcp-server-option
      |     |  +--rw enable                    boolean
      |     |  +--rw pcp-server* [pcp-serv-id]
      |     |     +--rw pcp-serv-id            uint8
      |     |     +--rw pcp-serv-addr*         inet:ipv6-address
      |     +--rw s46-rule-option
      |     |  +--rw enable                    boolean
      |     |  +--rw s46-rule* [rule-id]
      |     |     +--rw rule-id                uint8
      |     |     +--rw rule-type              enumeration
      |     |     +--rw ea-len                 uint8
      |     |     +--rw prefix4-len            uint8
      |     |     +--rw ipv4-prefix            inet:ipv4-prefix
      |     |     +--rw prefix6-len            uint8
      |     |     +--rw ipv6-prefix            inet:ipv6-prefix
      |     |     +--rw port-parameter
      |     |        +--rw offset              uint8
      |     |        +--rw psid-len            uint8
      |     |        +--rw psid                uint16
      |     +--rw s46-br-option
      |     |  +--rw enable                    boolean
      |     |  +--rw br* [br-id]
      |     |      +--rw br-id                 uint8
      |     |      +--rw br-ipv6-addr          inet:ipv6-address
      |     +--rw s46-dmr-option
      |     |  +--rw enable                    boolean
      |     |  +--rw dmr* [dmr-id]
      |     |     +--rw dmr-id                 uint8
      |     |     +--rw dmr-prefix6-len        uint8
      |     |     +--rw dmr-ipv6-prefix        inet:ipv6-prefix
      |     +--rw s46-v4-v6-binding-option
      |        +--rw enable                    boolean
      |        +--rw ce* [ce-id]
      |           +--rw ce-id                  uint8
      |           +--rw ipv4-addr              inet:ipv4-address
      |           +--rw bind-prefix6-len       uint8
      |           +--rw bind-ipv6-prefix       inet:ipv6-prefix
      |           +--rw port-parameter
      |              +--rw offset              uint8
      |              +--rw psid-len            uint8
      |              +--rw psid                uint16
      +--rw network-ranges
      |  +--rw option-set [option-set-id]
      |  +--rw network-range* [network-range-id]
      |     +--rw network-range-id             uint8
      |     +--rw network-description          string
      |     +--rw network-prefix               inet:ipv6-prefix
      |     +--rw inherit-option-set           boolean
      |     +--rw option-set [option-set-id]
      |     +--rw address-pools
      |     |  +--rw address-pool* [pool-id]
      |     |  |  +--rw pool-id                uint8
      |     |  |  +--rw pool-prefix            inet:ipv6-prefix
      |     |  |  +--rw start-address          inet:ipv6-address
      |     |  |  +--rw end-address            inet:ipv6-address
      |     |  |  +--rw preferred-lifetime     yang:timeticks
      |     |  |  +--rw valid-lifetime         yang:timeticks
      |     |  |  +--ro total-ipv6-count       uint64
      |     |  |  +--ro used-ipv6-count        uint64
      |     |  |  +--rw utilization-ratio      threshold
      |     |  |  +--rw inherit-option-set     boolean
      |     |  |  +--rw option-set [option-set-id]
      |     |  |  +--rw reserved-addresses
      |     |  |     +--rw static-binding* [cli-id]
      |     |  |     |  +--rw cli-id           uint32
      |     |  |     |  +--rw duid             duidtype
      |     |  |     |  +--rw reserv-addr*     inet:ipv6-address
      |     |  |     +--rw other-reserv-addr*  inet:ipv6-address
      |     |  +--ro binding-info* [cli-id]
      |     |     +--ro cli-id                 uint32
      |     |     +--ro duid                   duidtype
      |     |     +--ro cli-ia* [iaid]
      |     |        +--ro ia-type             string
      |     |        +--ro iaid                uint32
      |     |        +--ro cli-addr*           inet:ipv6-address
      |     |        +--ro pool-id?            uint8
      |     +--rw prefix-pools
      |     |  +--rw prefix-pool* [pool-id]
      |     |  |  +--rw pool-id                uint8
      |     |  |  +--rw prefix                 inet:ipv6-prefix
      |     |  |  +--rw prefix-length          uint8
      |     |  |  +--rw preferred-lifetime     yang:timeticks
      |     |  |  +--rw valid-lifetime         yang:timeticks
      |     |  |  +--rw utilization-ratio      threshold
      |     |  |  +--rw inherit-option-set     boolean
      |     |  |  +--rw option-set [option-set-id]
      |     |  |  +--rw reserved-prefixes
      |     |  |     +--rw static-binding* [cli-id]
      |     |  |     |  +--rw cli-id           uint32
      |     |  |     |  +--rw duid             duidtype
      |     |  |     |  +--rw reserv-prefix-len  uint8
      |     |  |     |  +--rw reserv-prefix    inet:ipv6-prefix
      |     |  |     +--rw exclude-prefix-len  uint8
      |     |  |     +--rw exclude-prefix      inet:ipv6-prefix
      |     |  |     +--rw other-reserv-prefix*  [reserv-id]
      |     |  |        +--rw reserv-id        uint8
      |     |  |        +--rw prefix-len       uint8
      |     |  |        +--rw prefix           inet:ipv6-prefix
      |     |  +--ro binding-info* [cli-id]
      |     |     +--ro cli-id                 uint32
      |     |     +--ro duid                   duidtype
      |     |     +--ro cli-iapd* [iaid]
      |     |        +--ro iaid                uint32
      |     |        +--ro cli-prefix*         uint32
      |     |        +--ro cli-prefix-len*     uint8
      |     |        +--ro pool-id?            uint8
      |     +--rw hosts
      |        +--rw host* [cli-id]
      |           +--rw cli-id                 uint32
      |           +--rw duid                   duidtype
      |           +--rw inherit-option-set     boolean
      |           +--rw option-set [option-set-id]
      |           +--rw nis-domain-name?       string
      |           +--rw nis-plus-domain-name?  string
      +--rw relay-opaque-paras
      |  +--rw relays* [relay-name]
      |     +--rw relay-name                   string
      |     +--rw interface-info* [if-name]
      |     |  +--rw if-name                   string
      |     |  +--rw interface-id              string
      |     +--rw subscribers* [subscriber]
      |     |  +--rw subscriber                uint8
      |     |  +--rw subscriber-id             string
      |     +--rw remote-host* [ent-num]
      |        +--rw ent-num                   uint32
      |        +--rw remote-id                 string
      +--rw rsoo-enabled-options
      |  +--rw rsoo-enabled-option* [option-code]
      |     +--rw option-code                  uint16
      |     +--rw description                  string
      +--ro packet-stats
         +--ro solicit-count                   uint32
         +--ro request-count                   uint32
         +--ro renew-count                     uint32
         +--ro rebind-count                    uint32
         +--ro decline-count                   uint32
         +--ro release-count                   uint32
         +--ro info-req-count                  uint32
         +--ro advertise-count                 uint32
         +--ro confirm-count                   uint32
         +--ro reply-count                     uint32
         +--ro reconfigure-count               uint32
         +--ro relay-forward-count             uint32
         +--ro relay-reply-count               uint32
          ]]></artwork>
        </figure>

        <t>Introduction of important nodes:</t>

        <t><list style="symbols">
        
          <t>serv-attributes: This container contains basic attributes 
          of a DHCPv6 server such as DUID, server name and so on. 
          Some optional functions that can be provided by the server 
          is also included.</t>

          <t>duid: Each server and client has only one DUID (DHCP 
          Unique Identifier). The DUID here identifies a unique 
          DHCPv6 server for clients. DUID consists of a two-octet 
          type field and an arbitrary length (no more than 128 bytes) 
          content field.</t>

          <t>pd-function: Whether the server can act as a delegating 
          router to perform prefix delegation (<xref target="RFC3633"/>).
          </t>
          
          <t>stateless-service: A boolean value specifies whether 
          the server support client-server exchanges involving two 
          messages defined in (<xref target="RFC3315"/>).</t>
          
          <t>rapid-commit: Setting the value to '1' represents the 
          server support the Solicit-Reply message exchange. '0' 
          means the server will simply ignore the Rapid Commit 
          option in Solicit message.</t>
          
          <t>option-sets: DHCPv6 employs various options to carry 
          additional information and parameters in DHCP messages. 
          This container defines all the possible options that need 
          to be configured at the server side. The relevant RFCs that 
          define those options include: <xref target="RFC3315"/>, 
          <xref target="RFC3319"/>, <xref target="RFC3646"/>, 
          <xref target="RFC3898"/>, <xref target="RFC4242"/>,
          <xref target="RFC4704"/>, <xref target="RFC4833"/>,
          <xref target="RFC5908"/>, <xref target="RFC5970"/>, 
          <xref target="RFC4075"/>, <xref target="RFC6334"/>, 
          <xref target="RFC6784"/>, <xref target="RFC7078"/>, 
          <xref target="RFC7083"/>, <xref target="RFC7291"/>, 
          <xref target="RFC7598"/>.</t>
          
          <t>option-set: A server may allow different option sets to 
          be configured for different conditions (i.e. different networks, 
          clients and etc). This "option-set" list enables various sets of 
          options being defined and configured in a single server. Different 
          sets are distinguished by the key called "option-set-id". All the 
          possible options discussed above are defined in the list and each 
          option is corresponding to a container. Since all the options in 
          the list are optional, each container in this list has a boolean 
          parameter called "enable" to indicate whether this option (container) 
          will be included in the current option set or not. With the 
		  "new-option" container, it is easy to extend the model when new 
		  options are defined.</t>

          <t>network-ranges: This model supports a hierarchy to achieve 
          dynamic configuration. That is to say we could configure the 
          server at different levels through this model. The top level is 
          a global level which is defined as the container "network-ranges". 
          The following levels are defined as sub-containers under it. The 
          "network-ranges" contains the parameters (e.g. option-sets) that 
          would be allocated to all the clients served by this server.</t>

          <t>network-range: Under the "network-ranges" container, a 
          "network-range" list is defined to configure the server at a 
          network level which is also considered as the second level. 
          Different network are identified by the key "network-range-id". 
          This is because a server may have different configuration 
          parameters (e.g. option sets) for different networks.</t>                       
          
          <t>address-pools: Under the "network-range" list, a container 
          describes the DHCPv6 server's address pools for a specific network 
          is defined. This container supports the server to be configured at 
          a pool level.</t>

          <t>address-pool: A DHCPv6 server can be configured with 
          several address pools for a specific network. This list defines 
          such address pools which are distinguish by the key called 
          "pool-id".</t>
          
          <t>binding-info: A list records a binding information for 
          each DHCPv6 client that has already been allocated IPv6 
          addresses.</t>
          
          <t>prefix-pools: If a server supports prefix delegation 
          function, this container under the "network-range" list will 
          be valid to define the delegating router's prefix pools for a 
          specific network. This container also supports the server to be 
          configured at a pool level.</t>
          
          <t>prefix-pool: Similar to server's address pools, a 
          delegating router can also be configured with multiple 
          prefix pools specified by a list called "prefix-pool".</t>
          
          <t>binding-info: A list records a binding information for 
          each DHCPv6 requesting router that has already been configured 
          IPv6 prefixes.</t>
          
          <t>hosts: A server may also desire to be configured at a host 
          level under some circumstances. This container include a list 
          called "host" to allow the server carrying different parameters 
          (e.g. option sets) for different hosts.</t>
          
          <t>relay-opaque-paras: This container contains some opaque values 
          in Relay Agent options that need to be configured on the server 
          side only for value match. Such Relay Agent options include 
          Interface-Id option, Remote-Id option and Subscriber-Id option.
          </t>
          
          <t>rsoo-enabled-options: <xref target="RFC6422"/> requires that the 
          server SHOULD have an administrator-configurable list of RSOO-enabled 
          options. This container include a list called "rsoo-enabled-option" to 
          allow new RSOO-enabled options to be defined at the server side.</t>

          <t>packet-stats: A container presents the packet statistics 
          related to the DHCPv6 server.</t>          

        </list></t>
      </section>

      <section anchor="dhcpv6-relay-tree" title="DHCPv6 Relay Tree Diagrams">
        <figure>
          <artwork><![CDATA[
+--rw dhcpv6
   +-- ...
   |
   +--rw relay                                 {dhcpv6-relay}?
      +--rw relay-attributes
      |  +--rw name                            string
      |  +--rw enable                          boolean
      |  +--rw ipv6-address                    inet:ipv6-address
      |  +--rw description?                    string
      |  +--rw dest-addrs*                     inet:ipv6-address
      |  +--rw subscribers* [subscriber]
      |  |  +--rw subscriber                   uint8
      |  |  +--rw subscriber-id                string
      |  +--rw remote-host* [entNum]
      |  |  +--rw ent-num                      uint32
      |  |  +--rw remote-id                    string
      |  +--rw vendor-info
      |     +--rw ent-num                      uint32
      |     +--rw data*                        string
      +--rw relay-supplied-options-option
      |  +--rw rsoo-set* [rsoo-set-id]
      |     +--rw rsoo-set-id               uint8
      |     +--rw erp-local-domain-name-option
      |        +--rw enable                 boolean
      |        +--rw erp-for-client* [cli-id]
      |           +--rw cli-id              uint32
      |           +--rw duid                duidtype
      |           +--rw erp-name            string
      +--rw relay-interfaces
      |  +--rw relay-if* [if-name]
      |     +--rw if-name                   string
      |     +--rw enable                    boolean
      |     +--rw interface-id?             string
      |     +--rw rsoo-set [rsoo-set-id]
      |     +--rw pd-route* [pd-route-id]
      |     |  +--rw pd-route-id            uint8
      |     |  +--rw requesting-router-id   uint32
      |     |  +--rw delegating-router-id   uint32
      |     |  +--rw next-router            inet:ipv6-address
      |     |  +--rw last-router            inet:ipv6-address
      |     +--rw next-entity* [dest-addr]
      |        +--rw dest-addr              inet:ipv6-address
      |        +--rw available              boolean
      |        +--rw multicast              boolean
      |        +--rw server                 boolean
      |        +--ro packet-stats
      |           +--ro cli-packet-rvd-count  uint32
      |           +--ro solicit-rvd-count     uint32
      |           +--ro request-rvd-count     uint32
      |           +--ro renew-rvd-count       uint32
      |           +--ro rebind-rvd-count      uint32
      |           +--ro decline-rvd-count     uint32
      |           +--ro release-rvd-count     uint32
      |           +--ro info-req-rvd-count    uint32
      |           +--ro relay-for-rvd-count   uint32
      |           +--ro relay-rep-rvd-count   uint32
      |           +--ro packet-to-cli-count   uint32
      |           +--ro adver-sent-count      uint32
      |           +--ro confirm-sent-count    uint32
      |           +--ro reply-sent-count      uint32
      |           +--ro reconfig-sent-count   uint32
      |           +--ro relay-for-sent-count  uint32
      |           +--ro relay-rep-sent-count  uint32
      +--ro relay-stats
         +--ro cli-packet-rvd-count            uint32
         +--ro relay-for-rvd-count             uint32
         +--ro relay-rep-rvd-count             uint32
         +--ro packet-to-cli-count             uint32
         +--ro relay-for-sent-count            uint32
         +--ro relay-rep-sent-count            uint32
         +--ro discarded-packet-count          uint32
          ]]></artwork>
        </figure>

        <t>Introduction of important nodes:</t>

        <t><list style="symbols">
        
          <t>relay-attributes: A container describes some basic 
          attributes of the relay agent including some relay agent 
          specific options data that need to be configured 
          previously. Such options include Remote-Id option and 
          Subscriber-Id option.</t>

          <t>dest-addrs: Each DHCPv6 relay agent may be configured with 
          a list of destination addresses. This node defines such a list 
          of IPv6 addresses that may include unicast addresses, multicast 
          addresses or other addresses.</t>

          <t>relay-supplied-options-option: DHCPv6 relay agent could 
          provide some information that would be useful to DHCPv6 
          client. Since relay agent cannot provide options directly 
          to the client, <xref target="RFC6422"/> defines RSOO-enabled 
          options to propose options for the server to send to the 
          client. This container modelled such RSOO-enabled options.</t>

          <t>rsoo-set: This list under the "relay-supplied-options-option" 
          container is similar to the "option-set" defined in server 
          feature. It allows the relay to implement several sets of 
          RSOO-enabled options for different interfaces. The list only 
          include the EAP Re-authentication Protocol (ERP) Local Domain 
          Name DHCPv6 Option defined in <xref target="RFC6440"/>, since 
          it is the only one RSOO-enabled options accepted by IANA so far.</t>          

          <t>relay-interfaces: The "relay-interfaces" defines common 
          configuration and state parameters of the interfaces 
          belonging to a DHCPv6 relay agent.</t>
          
          <t>relay-if: A list under "relay-interfaces" container that 
          describes a specific interface and its corresponding parameters. 
          Here we use a string called "if-name" as the key of list.</t>
          
          <t>pd-route: A sub-container of "relay-if" which describes 
          the route for delegated prefixes into the provider edge 
          router.</t>
          
          <t>next-entity: This node defines a list that is used to describe 
          the next hop entity of this relay agent. Different entities are 
          distinguished by their addresses.</t>
          
          <t>packet-stats: A container shows packet state information 
          of a specific data communication.</t>
          
          <t>relay-stats: The "relay-stats" container records and presents 
          the overall packet statistics of the relay agent.</t>

        </list></t>

      </section>

      <section anchor="dhcpv6-client-tree" title="DHCPv6 Client Tree Diagrams">
        <figure>
          <artwork><![CDATA[
+--rw dhcpv6
   +-- ...
   |
   +--rw client                                {dhcpv6-client}?
      +--rw client-interfaces
         +--rw client-if* [if-name]
            +--rw if-name                      string
            +--rw cli-id                       uint32
            +--rw duid                         duidtype
            +--rw enable                       boolean
            +--rw description?                 string
            +--rw pd-function                  boolean
            +--rw rapid-commit                 boolean
            +--rw mo-tab
            |  +--rw m-tab                     boolean
            |  +--rw o-tab                     boolean
            +--rw oro-options
            |  +--rw oro-option* [option-code]
            |     +--rw option-code            uint16
            |     +--rw description            string
            +--rw client-configured-options
            |  +--rw new-cli-option* [option-code]
            |  |  +--rw option-code            uint16
            |  |  +--rw option-name            string
            |  |  +--rw option-description     string
            |  |  +--rw option-reference?      string
            |  |  +--rw option-value           string
            |  +--rw user-class-option
            |  |  +--rw enable                 boolean
            |  |  +--rw user-class* [user-class-id]
            |  |     +--rw user-class-id       uint8
            |  |     +--rw user-class-info     string
            |  +--rw vendor-class-option
            |  |  +--rw enable                 boolean
            |  |  +--rw ent-num                uint32
            |  |  +--rw data*                  string
            |  +--rw client-fqdn-option
            |  |  +--rw enable                 boolean
            |  |  +--rw fqdn                   string
            |  |  +--rw server-initiate-update boolean
            |  |  +--rw client-initiate-update boolean
            |  +--rw client-architecture-type-option
            |  |  +--rw enable                 boolean
            |  |  +--rw architecture-types* [type-id]
            |  |  |  +--rw type-id             uint16
            |  |  |  +--rw most-preferred      boolean
            |  +--rw client-network-interface-option
            |  |  +--rw enable                 booelan
            |  |  +--rw type                   uint8
            |  |  +--rw major                  uint8
            |  |  +--rw minor                  uint8
            |  +--rw kerberos-principal-name-option
            |  |  +--rw enable                 boolean
            |  |  +--rw principal-name         string
            |  +--rw client-link-layer-addr-option
            |     +--rw enable                 boolean
            |     +--rw link-layer-type        uint16
            |     +--rw link-layer-addr        string
            +--ro identity-associations
            |  +--ro identity-association* [iaid]
            |     +--ro iaid                   uint32
            |     +--ro ia-type                string
            |     +--ro ipv6-addr*             inet:ipv6-address
            |     +--ro ipv6-prefix*           inet:ipv6-prefix
            |     +--ro prefix-length*         uint8   
            |     +--ro t1-time                yang:date-and-time
            |     +--ro t2-time                yang:date-and-time
            |     +--ro preferred-lifetime     yang:timeticks
            |     +--ro valid-lifetime         yang:timeticks
            +--ro if-other-paras
            |  +--ro uni-dhcpv6-serv-addr      inet:ipv6-address
            |  +--ro dns-paras
            |  |  +--ro domain-search-list     string
            |  |  +--ro dns-servers* [dns-serv-id]
            |  |     +--ro dns-serv-id         uint8
            |  |     +--ro dns-serv-addr       inet:ipv6-address
            |  +--ro sip-paras
            |  |  +--ro sip-servers* [sip-serv-id]
            |  |     +--ro sip-serv-id         uint8
            |  |     +--ro sip-serv-addr       inet:ipv6-address
            |  |     +--ro sip-serv-domain-name  string
            |  +--ro nis-paras
            |  |  +--ro nis-domain-name        string
            |  |  +--ro nis-server* [nis-serv-id]
            |  |     +--ro nis-serv-id         uint8
            |  |     +--ro nis-serv-addr       inet:ipv6-address
            |  +--ro nis-plus-paras
            |  |  +--ro nis-plus-domain-name   string
            |  |  +--ro nis-plus-server* [nis-plus-serv-id]
            |  |     +--ro nis-plus-serv-id    uint8
            |  |     +--ro nis-plus-serv-addr  inet:ipv6-address
            |  +--ro info-refresh-time         yang:timeticks
            |  +--ro time-zone-paras
            |  |  +--ro tz-posix               string
            |  |  +--ro tz-database            string
            |  +--ro cli-fqdn                  string
            |  +--ro ntp-paras
            |  |  +--ro ntp-server* [ntp-serv-id]
            |  |     +--ro ntp-serv-id         uint8
            |  |     +--ro ntp-serv-addr       inet:ipv6-address
            |  |     +--ro ntp-serv-mul-addr   inet:ipv6-address
            |  |     +--ro ntp-serv-fqdn       string
            |  +--ro sntp-paras
            |  |  +--ro sntp-server* [sntp-serv-id]
            |  |     +--ro sntp-serv-id         uint8
            |  |     +--ro sntp-serv-addr       inet:ipv6-address
            |  +--ro network-boot-paras
            |  |  +--ro boot-file* [boot-file-id]
            |  |     +--ro boot-file-id           uint8
            |  |     +--ro suitable-arch-type*    uint16
            |  |     +--ro suitable-net-if*       uint32
            |  |     +--ro boot-file-url          string
            |  |     +--ro boot-file-paras* [para-id]
            |  |        +--ro para-id             uint8
            |  |        +--ro parameter           string
            |  +--ro kerberos-paras
            |  |  +--ro default-realm-name        string
            |  |  +--ro kdc-info* [kdc-id]
            |  |     +--ro kdc-id                 uint8
            |  |     +--ro priority               uint16
            |  |     +--ro weight                 uint16
            |  |     +--ro transport-type         uint8
            |  |     +--ro port-number            uint16
            |  |     +--ro kdc-ipv6-addr          inet:ipv6-address
            |  |     +--ro realm-name             string
            |  +--ro addr-selection-paras
            |  |  +--ro automatic-row-add         boolean
            |  |  +--ro prefer-temporary-addr     boolean
            |  |  +--ro policy-table* [policy-id]
            |  |     +--ro policy-id              uint8
            |  |     +--ro label                  uint8
            |  |     +--ro precedence             uint8
            |  |     +--ro prefix-len             uint8
            |  |     +--ro prefix                 inet:ipv6-prefix            
            |  +--ro sol-max-rt                   yang:timeticks
            |  +--ro inf-max-rt                   yang:timeticks
            |  +--ro pcp-paras
            |  |  +--ro pcp-server* [pcp-serv-id]
            |  |     +--ro pcp-serv-id            uint8
            |  |     +--ro pcp-serv-addr          inet:ipv6-address
            |  +--ro s46-rule-paras
            |  |  +--ro s46-rule* [rule-id]
            |  |     +--ro rule-id                uint8
            |  |     +--ro rule-type              enumeration
            |  |     +--ro ea-len                 uint8
            |  |     +--ro prefix4-len            uint8
            |  |     +--ro ipv4-prefix            inet:ipv4-prefix
            |  |     +--ro prefix6-len            uint8
            |  |     +--ro ipv6-prefix            inet:ipv6-prefix
            |  |     +--ro port-parameter
            |  |        +--ro offset              uint8
            |  |        +--ro psid-len            uint8
            |  |        +--ro psid                uint16
            |  +--ro s46-br-paras
            |  |  +--ro br* [br-id]
            |  |     +--ro br-id                  uint8
            |  |     +--ro br-ipv6-addr           inet:ipv6-address
            |  +--ro s46-dmr-paras
            |  |  +--ro dmr* [dmr-id]
            |  |     +--ro dmr-id                 uint8
            |  |     +--ro dmr-prefix6-len        uint8
            |  |     +--ro dmr-ipv6-prefix        inet:ipv6-prefix
            |  +--ro s46-v4-v6-binding-paras
            |  |  +--ro ipv4-addr                 inet:ipv6-address
            |  |  +--ro bind-prefix6-len          uint8
            |  |  +--ro port-parameter
            |  |     +--ro offset                 uint8
            |  |     +--ro psid-len               uint8
            |  |     +--ro psid                   uint16
            |  +--ro erp-local-domain-name        string
            +--ro supported-options
            |  +--ro supported-option* [option-code]
            |     +--ro option-code            uint16
            |     +--ro description            string
            +--ro packet-stats
               +--ro solicit-count             uint32
               +--ro request-count             uint32
               +--ro renew-count               uint32
               +--ro rebind-count              uint32
               +--ro decline-count             uint32
               +--ro release-count             uint32
               +--ro info-req-count            uint32
               +--ro advertise-count           uint32
               +--ro confirm-count             uint32
               +--ro reply-count               uint32
               +--ro reconfigure-count         uint32
          ]]></artwork>
        </figure>

        <t>Introduction of important nodes:</t>

        <t><list style="symbols">
        
          <t>client-interfaces: A client may have several interfaces, 
          it is more reasonable to configure and manage parameters on 
          the interface-level. This container includes configuration 
          and state data of a DHCPv6 client in a per-interface manner.
          </t>
          
          <t>client-if: The list defines a specific client interface 
          and its data. Different interfaces are distinguished by the 
          "ifName" key which is a configurable string value.</t>

          <t>duid: Each server and client has only one DUID (DHCP 
          Unique Identifier). The DUID here will be carried in the 
          Client ID option to identify a specific DHCPv6 client. This 
          leaf are same as the "duid" leaf in "dhcpv6-server" 
          feature.</t>

          <t>pd-function: Whether the client can act as a requesting 
          router to request prefixes using prefix delegation 
          (<xref target="RFC3633"/>).</t>
          
          <t>rapid-commit: '1' indicates a client can initiate a 
          Solicit-Reply message exchange by adding a Rapid Commit 
          option in Solicit message. '0' means the client is not 
          allowed to add a Rapid Commit option to request addresses 
          in a two-message exchange pattern.</t>

          <t>mo-tab: The management tab label indicates the operation 
          mode of the DHCPv6 client. 'm'=1 and 'o'=1 indicate the 
          client will use DHCPv6 to obtain all the configuration 
          data. 'm'=1 and 'o'=0 are a meaningless combination. 
          'm'=0 and 'o'=1 indicate the client will use stateless 
          DHCPv6 to obtain configuration data apart from 
          addresses/prefixes data. 'm'=0 and 'o'=0 represent the 
          client will not use DHCPv6 but use SLAAC to achieve 
          configuration.</t>
          
          <t>oro-options: This container provide a way to configure 
          the list of options that the client will request in its 
          ORO option.</t>

          <t>client-configured-options: Similar to the server, the 
          client also need to configure some options to fulfil some 
          desired functions. This container include all the potential 
          options that need to be configured at the client side. The 
          relevant RFCs that define those options include: 
          <xref target="RFC3315"/>, <xref target="RFC4704"/>, 
          <xref target="RFC5970"/>, <xref target="RFC6784"/>, 
          <xref target="RFC6939"/>.</t>
          

          <t>identity-association: IA is a construct through which a 
          server and a client can identify, group, and manage a set of 
          related IPv6 addresses. The key of the "identity-association" 
          list is a 4-byte number IAID defined in <xref target="RFC3315"/>
          .</t>
          
          <t>if-other-paras: A client can obtain extra configuration 
          data other than address and prefix information through 
          DHCPv6 options. This container describes such data the client 
          was configured through DHCPv6. The potential configuration data 
          may include DNS server parameters, SIP server parameters and 
          etc.</t>
          
          <t>supported-options: This state data container defines a 
          list of options supported by the client for administrator 
          to interrogate a client's capabilities.</t>
          
          <t>packet-stats: A container records all the packet status 
          information of a specific interface.</t>

        </list></t>

      </section>
      
      <section anchor="dhcpv6-notifications" title="Notifications Mechanism for DHCPv6">
        <figure>
          <artwork><![CDATA[
+--rw dhcpv6
   +-- ...
   |
   +--n notifications
      +--n dhcpv6-server-event                 {dhcpv6-server}?
      |  +--n pool-running-out
      |  |  +--ro utilization-ratio            uint16
      |  |  +--ro duid                         duidtype      
      |  |  +--ro serv-name?                   string
      |  |  +--ro pool-name                    string
      |  +--n invalid-client-detected
      |     +--ro duid                         duidtype
      |     +--ro description?                 string      
      +--n dhcpv6-relay-event                  {dhcpv6-relay}?
      |  +--n topo-changed
      |     +--ro relay-if-name                string
      |     +--ro first-hop                    boolean
      |     +--ro last-entity-addr             inet:ipv6-address
      +--n dhcpv6-client-event                 {dhcpv6-client}?
         +--n ia-lease-event
         |  +--ro event-type                   enumeration
         |  +--ro duid                         duidtype
         |  +--ro iaid                         uint32
         |  +--ro serv-name?                   string
         |  +--ro description?                 string
         +--n invalid-ia-detected
         |  +--ro duid                         duidtype                
         |  +--ro iaid                         uint32
         |  +--ro serv-name?                   string
         |  +--ro description?                 string
         +--n retransmission-failed
         |  +--ro duid                         duidtype
         |  +--ro description                  enumeration
         +--n failed-status-turn-up
            +--ro duid                         duidtype
            +--ro status-code                  enumeration
          ]]></artwork>
        </figure>
        
        <t>Introduction of notifications:</t>

        <t><list style="symbols">
        
          <t>pool-running-out: raised when the address/prefix pool 
          is going to run out. A threshold for utilization ratio of 
          the pool has been defined in the server feature so that it 
          will notify the administrator when the utilization ratio 
          reaches the threshold, and such threshold is a settable 
          parameter.          
          </t>
          
          <t>invalid-client-detected: raised when the server 
          has found a client which can be regarded as a potential 
          attacker. Some description could also be included.
          </t>
          
          <t>topo-changed: raised when the topology of the relay 
          agent is changed.
          </t>
		  
          <t>ia-lease-event: raised when the client was allocated 
          a new IA from the server or it renew/rebind/release its 
          current IA.
          </t>
          
          <t>invalid-ia-detected: raised when the identity 
          association of the client can be proved to be invalid. 
          Possible condition includes duplicated address, illegal 
          address, etc.
          </t>
          
          <t>retransmission-failed: raised when the retransmission 
          mechanism defined in <xref target="RFC3315"/> is failed.
          </t>
          
          <t>failed-status-turn-up: raised when the client receives 
          a message includes an unsuccessful Status Code option.
          </t>
          
        </list></t>

      </section>

    </section>

    <section anchor="yang-model" title="DHCPv6 YANG Model">
      <t>This module imports typedefs from <xref target="RFC6991"></xref>.</t>

      <figure>
        <artwork><![CDATA[
<CODE BEGINS> file "ietf-dhcpv6@2015-09-25.yang"

module ietf-dhcpv6 {
    namespace "urn:ietf:params:xml:ns:yang:ietf-dhcpv6";
    prefix "dhcpv6";
    
    import ietf-inet-types { 
        prefix inet; 
        revision-date "2013-07-15"; 
    }
    import ietf-yang-types { 
        prefix yang; 
        revision-date "2013-07-15"; 
    }
    
    organization "dhc wg";
    contact "yong@csnet1.cs.tsinghua.edu.cn 
            wangh13@mails.tsinghua.edu.cn 
            lh.sunlinh@gmail.com 
            Ted.Lemon@nominum.com 
            ian.farrer@telekom.de";
    
    description "This model defines a YANG data model that can be 
	used to configure and manage DHCPv6 server, DHCPv6 relay and 
    DHCPv6 client.";

    revision 2015-09-25 { 
        description "version04: Correct duid and grammar errors.";
		
        reference "I-D: draft-cui-dhc-dhcpv6-yang-04"
    }
    revision 2015-07-01 { 
        description "version03: Correct grammar errors.";
		
        reference "I-D: draft-cui-dhc-dhcpv6-yang-03"
    }
    revision 2015-04-13 { 
        description "version02: Correct grammar errors.";
		
        reference "I-D: draft-cui-dhc-dhcpv6-yang-02"
    }
    revision 2015-04-02 { 
        description "version01: Correct grammar errors, Reuse 
	    groupings, Update 'dhcpv6-realy' feature, Add 
		notifications.";
		
        reference "I-D: draft-cui-dhc-dhcpv6-yang-01"
    }
    revision 2015-03-04 { 
        description "version00: Initial revision.";
		
        reference "I-D: draft-cui-dhc-dhcpv6-yang-00"
    }


/*
 * Features
 */

    feature dhcpv6-server {
        description
            "Server in DHCPv6.";
        reference
            "RFC3315";
    }

    feature dhcpv6-relay {
        description
            "Relay agent in DHCPv6.";
        reference
            "RFC3315";
    }

    feature dhcpv6-client {
        description
             "Client in DHCPv6.";
        reference
               "RFC3315";
    }
/*
 * Typedef
 */
 
    typedef duidtype {
	    type union {
		    type uint16 {
			    description
				"This uint16 specifies the type of this duid";
			}
			type string {
			    pattern '(([0-9a-fA-F]{2}){2,128})';
			    description
                "This should be a variable length value 
                no more than 128 octets."
			}
		}
	}
    
    typedef threshold { 
        description "Threshold value in percent"; 
        type union { 
            type uint16 { 
                range 0..100;
                description "threshold value";
            } 
            type enumeration { 
                enum "disabled" { 
                    description "No threshold"; 
                } 
            } 
        } 
    }
/*
 * Grouping
 */

    grouping vendor-infor {
        container vendor-info {
            description "";
            leaf ent-num {
                type uint32;
                mandatory true;
                description "enterprise number";
            }
            leaf-list data {
                type string;
                description "specific vendor info";
            }
        }
    }

    grouping portset-para {
        container port-parameter {
            leaf offset {
                type uint8;
                mandatory true;
                description "offset in a port set";				
            }
            leaf psid-len {
                type uint8;
                mandatory true;
                description "length of a psid";				
            }
            leaf psid {
                type uint16;
                mandatory true;
                description "psid value";				
            }
        }
    }
    
/*
 * Data Nodes
 */

    container server {
        if-feature dhcpv6-server;
         description "server portion";
        container serv-attributes {
            description "This container contains basic attributes 
            of a DHCPv6 server such as DUID, server name and so 
            on. Some optional functions that can be provided by 
            the server is also included.";
            leaf name {
                type string;
                mandatory true;
                description "server's name";
            }
            leaf duid {
			    type duidtype;
                mandatory true;
                description "DHCP Unique Identifer";
			}
            leaf enable {
                type boolean;
                mandatory true;
                description "whether to enable the server";
            }
            leaf ipv6-address {
                type inet:ipv6-address;
                mandatory true;
                description "server's IPv6 address";
            }
            leaf description {
                type string;
                description "description of the server";
            }
            leaf pd-function {
                type boolean;
                mandatory true;
                description "Whether the server can act as a 
                delegating router to perform prefix delegation 
				([RFC3633]).";
            }
            leaf stateless-service {
                type boolean;
                mandatory true;
                description "A boolean value specifies whether 
                the server support client-server exchanges 
                involving two messages defined in ([RFC3315]).";
            }
            leaf rapid-commit {
                type boolean;
                mandatory true;
                description "A boolean value specifies whether 
                the server support client-server exchanges 
                involving two messages defined in ([RFC3315]).";
            }
            leaf store-client-link-layer {
                type boolean;
                description "whether to store the clients' 
                link-layer addresses";
            }
            uses vendor-infor;
            }
        container option-sets {
            description "*";
            list option-set {
                key option-set-id;
                description "*";
                leaf option-set-id {
                    type uint8; 
                    mandatory true; 
                    description "the option-set-id key";					
                }
				list new-option {
                    key option-code;
                    description "*";
                    leaf option-code {
                        type uint16;
                        manadatory true;
                        description "the option code key";
                    }
                    leaf option-name {
                        type string;
                        manadatory true;
                        description "the new option's name";
                    }
                    leaf option-description {
                        type string;
                        manadatory true;
                        description "description of new option";
                    }
                    leaf option-reference {
                        type string;
                        description "reference to the 
                        specification";
                    }
                    leaf option-value {
                        type string;
                        manadatory true;
                        description "the new option's value";
                    }
                }
                leaf user-class-value {
                    type string;
                    description "use class option's value";                    
                }
                leaf enterprise-number {
                    type uint32;
                    description "*";                    
                }
                leaf store-client-link-layer {
                    type boolean;
                    description "*";                    
                }
                container preference-option {
                    description "*";
                    leaf enable {
                        type boolean; 
                        mandatory true;
                        description "*";						
                    }
                    leaf preference-value {
                        type uint8;
                        mandatory true;
                        description "*";						
                    }
                }
                container sip-server-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list sip-server {
                        key sip-serv-id;
                        leaf sip-serv-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf sip-serv-domain-name {
                            type string; 
                            mandatory true;
                            description "*";							
                        }
                        leaf sip-serv-addr {
                            type inet:ipv6-address; 
                            mandatory true;
                            description "*";							
                        }
                    }
                }
                container dns-config-option {
                    description "*";
                    leaf enable {
                        type boolean; 
                        mandatory true;
                        description "*";						
                    }
                    list dns-server {
                        key dns-serv-id;
                        leaf dns-serv-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf dns-serv-addr {
                            type inet:ipv6-address; 
                            mandatory true;
                            description "*";							
                        }
                    }
                    leaf domain-search-list {
                        type string; 
                        mandatory true;
                        description "*";						
                    }
                }
                container nis-config-option {
                    description "*";
                    leaf enable {
                        type boolean; 
                        mandatory true;
                        description "*";						
                    }
                    list nis-server {
                        key nis-serv-id;
                        description "*";
                        leaf nis-serv-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf nis-serv-addr {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";							
                        }
                    }
                }
                container nis-plus-config-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list nis-plus-server {
                        key nis-plus-serv-id;
                        description "*";
                        leaf nis-plus-serv-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf nis-plus-serv-addr {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";							
                        }
                    }
                }                    
                container info-refresh-time-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf info-refresh-time {
                        type yang:timeticks;
                        mandatory true;
                        description "*";						
                    }
                }
                container cli-fqdn-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf server-initiate-update {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf client-initiate-update {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf modify-name-from-cli {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                }                    
                container timezone-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf tz-posix {
                        type string;
                        mandatory true;
                        description "*";						
                    }
                    leaf tz-database {
                        type string;
                        mandatory true;
                        description "*";						
                    }
                }
                container ntp-server-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list ntp-server {
                        key ntp-serv-id;
                        description "*";
                        leaf ntp-serv-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf ntp-serv-addr {
                            type inet:ipv6-address;
                            mandatory true;	
                            description "*";							
                        }
                        leaf ntp-serv-mul-addr {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";							
                        }
                        leaf ntp-serv-fqdn {
                            type string;
                            mandatory true;
                            description "*";							
                        }
                    }
                }                    
                container sntp-server-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list sntp-server {
                        key sntp-serv-id;
                        description "*";
                        leaf sntp-serv-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf sntp-serv-addr {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";							
                        }
                    }
                }                    
                container network-boot-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list boot-file {
                        key boot-file-id;
                        description "*";
                        leaf boot-file-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf-list suitable-arch-type {
                            type uint16;
                            description "*";							
                        }
                        leaf-list suitable-net-if {
                            type uint32;
                            description "*";							
                        }
                        leaf boot-file-url {
                            type string;
                            mandatory true;
                            description "*";							
                        }
                        list boot-file-paras {
                            key para-id;
                            description "*";
                            leaf para-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf parameter {
                                type string;
                                mandatory true;
                                description "*";								
                            }
                        }
                    }
                }                    
                container dslite-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf dslite-aftr-name {
                        type string;
                        mandatory true;
                        description "*";						
                    }
                }
                container kerberos-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf default-realm-name {
                        type string;
                        mandatory true;
                        description "*";						
                    }
                    list kdc-info {
                        key kdc-id;
                        description "*";
                        leaf kdc-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf priority {
                            type uint16;
                            mandatory true;
                            description "*";							
                        }
                        leaf weight {
                            type uint16;
                            mandatory true;
                            description "*";							
                        }
                        leaf transport-type {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf port-number {
                            type uint16;
                            mandatory true;
                            description "*";							
                        }
                        leaf kdc-ipv6-addr {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";							
                        }
                        leaf realm-name {
                            type string;
                            mandatory true;
                            description "*";							
                        }
                    }
                }                    
                container addr-selection-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf a-bit-set {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf p-bit-set {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list policy-table {
                        key policy-id;
                        description "*";
                        leaf policy-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf label {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf precedence {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf prefix-len {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf prefix {
                            type inet:ipv6-prefix;
                            mandatory true;
                            description "*";							
                        }
                    }
                }                      
                container sol-max-rt-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf sol-max-rt-value {
                        type yang:timeticks;
                        mandatory true;
                        description "*";						
                    }
                }                    
                container inf-max-rt-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf inf-max-rt-value {
                        type yang:timeticks;
                        mandatory true;
                        description "*";						
                    }
                }                    
                container pcp-server-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list pcp-server {
                        key pcp-serv-id;
                        description "*";
                        leaf pcp-serv-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf pcp-serv-addr {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";							
                        }
                    }
                }                    
                container s46-rule-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list s46-rule {
                        key rule-id;
                        description "*";
                        leaf rule-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf rule-type {
                            type enumeration {
                            enum "BMR";
                            enum "FMR";
                            }
                            mandatory true;
                            description "*";							
                        }
                        leaf prefix4-len {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf ipv4-prefix {
                            type inet:ipv4-prefix;
                            mandatory true;
                            description "*";							
                        }
                        leaf prefix6-len {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf ipv6-prefix {
                            type inet:ipv6-prefix;
                            mandatory true;
                            description "*";							
                        }
                        uses portset-para;
                    }
                }                    
                container s46-br-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list br {
                        key br-id;
                        description "*";
                        leaf br-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf br-ipv6-addr {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";							
                        }
                    }
                }                    
                container s46-dmr-option {
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list dmr {
                        key dmr-id;
                        description "*";
                        leaf dmr-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf dmr-prefix-len {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf dmr-ipv6-prefix {
                            type inet:ipv6-prefix;
                            mandatory true;
                            description "*";							
                        }
                    }
                }                    
                container s46-v4-v6-binding-option {
                    description "*";
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    list ce {
                        key ce-id;
                        description "*";
                        leaf ce-id {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf ipv4-addr {
                            type inet:ipv4-address;
                            mandatory true;
                            description "*";							
                        }
                        leaf bind-prefix6-len {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        leaf bind-ipv6-prefix {
                            type inet:ipv6-prefix;
                            mandatory true;
                            description "*";							
                        }
                        uses portset-para;
                    }
                }                    
            }
        }
            container network-range {
                description "*";
                leaf-list option-set {
                    type uint8;
                    description "*";					
                }
                list network-range {
                    key network-range-id;
                    description "*";
                    leaf network-range-id {
                        type uint8;
                        mandatory true;
                        description "*";						
                    }
                    leaf network-description {
                        type string;
                        mandatory true;
                        description "*";						
                    }
                    leaf network-prefix {
                        type inet:ipv6-prefix;
                        mandatory true;
                        description "*";						
                    }
                    leaf inherit-option-set {
                        type boolean;
                        mandatory true;
                        description "*";						
                    }
                    leaf-list option-set {
                        type uint8;
                        description "*";						
                    }
                    container address-pools {
                        description "A container describes 
                        the DHCPv6 server's address pools.";
                        list address-pool {
                            key pool-id;
                            description "A DHCPv6 server can 
                            be configured with several address 
                            pools. This list defines such 
                            address pools which are distinguish 
                            by the key called 'pool-name'.";
                            leaf pool-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf pool-prefix {
                                type inet:ipv6-prefix;
                                mandatory true;
                                description "*";
                            }
                            leaf start-address {
                                type inet:ipv6-address-no-zone;
                                mandatory true;
                                description "*";
                            }
                            leaf end-address {
                                type inet:ipv6-address-no-zone;
                                mandatory true;
                                description "*";
                            }
                            leaf preferred-lifetime {
                                type yang:timeticks;
                                mandatory true;
                                description "*";
                            }
                            leaf valid-lifetime {
                                type yang:timeticks;
                                mandatory true;
                                description "*";
                            }
                            leaf total-ipv6-count {
                                type uint64;
                                config "false";
                                mandatory true;
                                description "*";
                            }
                            leaf used-ipv6-count {
                                type uint64;
                                config "false";
                                mandatory true;
                                description "*";
                            }
                            leaf utilization-ratio {
                                type threshold;
                                mandatory true;
                                description "*";
                            }
                            leaf inherit-option-set {
                                type boolean;
                                mandatory true;
                                description "*";
                            }
                            leaf-list option-set {
                                type uint8;
                                description "*";								
                            }
                            container reserved-addresses {
                                description "*";
                                list static-binding {
                                    key cli-id;
                                    description "*";
                                    leaf cli-id {
                                        type uint32;
                                        mandatory true;
                                        description "*";
                                    }
                                    leaf duid {
                                        type duidtype;
                                        mandatory true;
                                        description "DHCP Unique 
                                        Identifer";
                                    }
                                    leaf-list reserv-addr {
                                        type inet:ipv6-address;
                                        description "*";
                                    }
                                }
                                leaf-list other-reserv-addr {
                                    type inet:ipv6-address;
                                    description "*";
                                }
                            }
                        }
                        list binding-info {
                            key cli-id;
                            config "false";
                            description "A list records a binding 
                            information for each DHCPv6 client 
                            that has already been allocated IPv6 
                            addresses.";
                            leaf cli-id {
                                type uint32;
                                mandatory true;
                                description "*";	
                            }
                            leaf duid {
                                type duidtype;
                                mandatory true;
								description "DHCP Unique Identifer";
							}
                            list cli-ia {
                                key iaid;
                                description "*";
                                leaf ia-type {
                                    type string;
                                    mandatory true;
                                    description "*";
                                }
                                leaf iaid {
                                    type uint32;
                                    mandatory true;
                                    description "*";
                                }
                                leaf-list cli-addr {
                                    type inet:ipv6-address;
                                    description "*";
                                }
                                leaf pool-id {
                                    type uint8;
                                    mandatory true;
                                    description "*";
                                }
                            }
                        }
                    }                    
                    container prefix-pools {
                        description "If a server supports prefix 
                        delegation function, this container will 
                        be used to define the delegating router's 
                        refix pools.";
                        list prefix-pool {
                            key pool-id;
                            description "Similar to server's 
                            address pools, a delegating router 
                            can also be configured with multiple 
                            prefix pools specified by a list 
                            called 'prefix-pool'.";
                            leaf pool-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf prefix {
                                type inet:ipv6-prefix;
                                mandatory true;
                                description "*";
                            }
                            leaf prefix-length {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf preferred-lifetime {
                                type yang:timeticks;
                                mandatory true;
                                description "*";
                            }
                            leaf valid-lifetime {
                                type yang:timeticks;
                                mandatory true;
                                description "*";
                            }
                            leaf utilization-ratio {
                                type threshold;
                                mandatory true;
                                description "*";
                            }
                            leaf inherit-option-set {
                                type boolean;
                                mandatory true;
                                description "*";
                            }
                            leaf-list option-set {
                                type uint8;
                                description "*";								
                            }
                            container reserved-prefixes {
                                description "*";
                                list static-binding {
                                    key cli-id;
                                    description "*";
                                    leaf cli-id {
                                        type uint32;
                                        mandatory true;
                                        description "*";
                                    }
                                    leaf duid {
                                        type duidtype;
                                        mandatory true;
                                        description "DHCP Unique 
										Identifer";
                                    }
                                    leaf reserv-prefix-len {
                                        type uint8;
                                        mandatory true;
                                        description "*";
                                    }
                                    leaf reserv-prefix {
                                        type inet:ipv6-prefix;
                                        mandatory true;
                                        description "*";
                                    }
                                }
                                leaf exclude-prefix-len {
                                    type uint8;
                                    mandatory true;
                                    description "*";
                                }
                                leaf exclude-prefix {
                                    type inet:ipv6-prefix;
                                    mandatory true;
                                    description "*";
                                }
                                list other-reserv-prefix {
                                    key reserv-id;
                                    description "*";
                                    leaf reserv-id {
                                        type uint8;
                                        mandatory true;
                                        description "*";
                                    }
                                    leaf prefix-len {
                                        type uint8;
                                        mandatory true;
                                        description "*";
                                    }
                                    leaf prefix {
                                        type inet:ipv6-prefix;
                                        mandatory true;
                                        description "*";
                                    }
                                }
                            }
                        }
                        list binding-info {
                            key cli-id;
                            config "false";
                            description "A list records a 
                            binding information for each 
                            DHCPv6 client that has already 
                            been allocated IPv6 addresses.";
                            leaf cli-id {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf duid {
                                type duidtype;
                                manadatory true;
                                description "DHCP Unique 
                                Identifier";
                            }
                            list cli-iapd {
                                key iaid;
                                description "*";
                                leaf iaid {
                                    type uint32;
                                    mandatory true;
                                    description "*";
                                }
                                leaf-list cli-prefix {
                                    type inet:ipv6-prefix;
                                    description "*";
                                }
                                leaf-list cli-prefix-len {
                                    type uint8;
                                    description "*";
                                }
                                leaf pool-id {
                                    type uint8;
                                    mandatory true;
                                    description "*";
                                }
                            }
                        }
                    }
                    container hosts {
                        description "*";
                        list host {
                            key cli-id;
                            description "*";
                            leaf cli-id {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf duid {
                                type duidtype;
                                mandatory true;
                                description "DHCP Unique 
                                Identifer";
                            }
                            leaf inherit-option-set {
                                type boolean;
                                mandatory true;
                                description "*";
                            }
                            leaf-list option-set {
                                type uint8;
                                description "*";
                            }
                            leaf nis-domain-name {
                                type string;
                                description "*";
                            }
                            leaf nis-plus-domain-name {
                                type string;
                                description "*";
                            }
                        }
                    }
                }
            }
            container relay-opaque-paras {
                description "This container contains some 
                opaque values in Relay Agent options that 
                need to be configured on the server side 
                only for value match. Such Relay Agent 
                options include Interface-Id option, 
                Remote-Id option and Subscriber-Id option.";
                list relays {
                    key relay-name;
                    description "*";
                    leaf relay-name {
                        type string;
                        mandatory true;
                        description "*";
                    }
                    list interface-info {
                        key if-name;
                        description "*";
                        leaf if-name {
                            type string;
                            mandatory true;
                            description "*";
                        }
                        leaf interface-id {
                            type string;
                            mandatory true;
                            description "*";
                        }
                    }
                    list subscribers {
                        key subscriber;
                        description "*";
                        leaf subscriber {
                            type uint8;
                            mandatory true;
                            description "*";
                        }
                        leaf subscriber-id {
                            type string;
                            mandatory true;
                            description "*";
                        }
                    }
                    list remote-host {
                        key ent-num;
                        description "*";
                        leaf ent-num {
                            type uint32;
                            mandatory true;
                            description "*";
                        }
                        leaf remote-id {
                            type string;
                            mandatory true;
                            description "*";
                        }
                    }
                }
            }
            container rsoo-enabled-options {
                description "*";
                list rsoo-enabled-option{
                    key option-code;
                    description "*";
                    leaf option-code {
                        type uint16;
                        mandatory true;
                        description "*";
                    }
                    leaf description {
                        type string;
                        mandatory true;
                        description "*";
                    }                    
                }
            }
            container packet-stats {
                config "false";
                description "A container presents 
                the packet statistics related to 
                the DHCPv6 server.";
                leaf solicit-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf request-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf renew-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf rebind-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf decline-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf release-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf info-req-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf advertise-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf confirm-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf reply-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf reconfigure-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf relay-forward-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf relay-reply-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
            }
        }
    }
    container relay {
        if-feature dhcpv6-relay;
        description "relay portion";
        container relay-attributes {
            description "A container describes 
            some basic attributes of the relay 
            agent including some relay agent 
            specific options data that need to 
            be configured previously. Such options 
            include Remote-Id option and 
            Subscriber-Id option.";
            leaf name {
                type string;
                mandatory true;
                description "*";
            }
            leaf enable {
                type boolean;
                mandatory true;
                description "*";
            }
            leaf ipv6-address {
                type inet:ipv6-address;
                mandatory true;
                description "*";
            }
            leaf description {
                type string;
                description "*";
            }
            leaf-list dest-addrs {
                type inet:ipv6-address;
                description "Each DHCPv6 relay agent may 
                be configured with a list of destination 
                addresses. This node defines such a list 
                of IPv6 addresses that may include 
                unicast addresses, multicast addresses 
                or other addresses.";
            }
            list subscribers {
                key subscriber;
                description "*";
                leaf subscriber {
                    type uint8;
                    mandatory true;
                    description "*";
                }
                leaf subscriber-id {
                    type string;
                    mandatory true;
                    description "*";
                }
            }
            list remote-host {
                key ent-num;
                description "*";
                leaf ent-num {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf remote-id {
                    type string;
                    mandatory true;
                    description "*";
                }
            }
            uses vendor-infor;
            container relay-supplied-options-option {
                description "*";
                list rsoo-set {
                    key rsoo-set-id;
                    description "*";
                    leaf rsoo-set-id {
                        type uint8;
                        mandatory true;
                        description "*";
                    }
                    container erp-local-domain-name-option {
                        description "*";
                        leaf enable {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        list erp-for-client {
                            key cli-id;
                            description "*";
                            leaf cli-id {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf duid {
                                type duidtype;
                                mandatory true;
                                description "DHCP Unique 
                                Identifer";
                            }
                            leaf erp-name {
                                type string;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                }
            }
            container relay-interfaces {
                description "It is a container that 
                defines common configuration and 
                state parameters in the interfaces 
                of a DHCPv6 relay agent. In this YANG 
                data model for DHCPv6 relay agent, 
                the parameters are configured in a 
                per-interface manner.";
                list relay-if {
                    key if-name;
                    description "A list describes a 
                    specific interface and its 
                    corresponding parameters. Here 
                    we use a string called 'ifName' 
                    as the key of list.";
                    leaf if-name {
                        type string;
                        mandatory true;
                        description "*";
                    }
                    leaf enable {
                        type boolean;
                        mandatory true;
                        description "*";
                    }
                    leaf interface-id {
                        type string;
                        description "*";
                    }
                    leaf-list rsoo-set {
                        type uint8;
                        description "*";
                    }
                    list pd-route {
                        key pd-route-id;
                        description "*";
                        leaf pd-route-id {
                            type uint8;
                            mandatory true;
                            description "*";
                        }
                        leaf requesting-router-	d {
                            type uint32;
                            mandatory true;
                            description "*";
                        }
                        leaf delegating-router-id {
                            type uint32;
                            mandatory true;
                            description "*";
                        }
                        leaf next-router {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";
                        }
                        leaf last-router {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";
                        }
                    }
                    list next-entity {
                        key dest-addr;
                        description "This node defines 
                        a list that is used to describe 
                        the next hop entity of this 
                        relay distinguished by their 
                        addresses.";
                        leaf dest-addr {
                            type inet:ipv6-address;
                            mandatory true;
                            description "*";
                        }
                        leaf available {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        leaf multicast {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        leaf server {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        container packet-stats {
                            config "false";
                            description "*";
                            leaf cli-packet-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf solicit-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf request-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf renew-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf rebind-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf decline-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf release-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf info-req-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf relay-for-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf relay-rep-rvd-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf packet-to-cli-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf adver-sent-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf confirm-sent-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf reply-sent-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf reconfig-sent-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf relay-for-sent-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                            leaf relay-rep-sent-count {
                                type uint32;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                }
            }
            container relay-stats {
                config "false";
                description "*";
                leaf cli-packet-rvd-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf relay-for-rvd-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf relay-rep-rvd-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf packet-to-cli-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf relay-for-sent-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf relay-rep-sent-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf discarded-packet-count {
                    type uint32;
                    mandatory true;
                    description "*";
                }
            }
        }
    }
    container client {
        if-feature dhcpv6-client;
        description "DHCPv6 Client Portion";
        container client-interfaces {
            description "A client may have several 
            interfaces, it is more reasonable to 
            configure and manage parameters on 
            the interface-level. This container 
            includes configuration and state data 
            of a DHCPv6 client in a per-interface 
            manner.";
            list client-if {
                key if-name;
                description "The list defines a 
                specific client interface and its 
                data. Different interfaces are 
                distinguished by the key which 
                is a configurable string value.";
                leaf if-name {
                    type string;
                    mandatory true;
                    description "interface name";
                }
                leaf cli-id {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf duid {
                    type duidtype;
                    mandatory true;
                    description "DHCP Unique 
                    Identifer";
                }
                leaf enable {
                    type boolean;
                    mandatory true;
                    description "*";
                }
                leaf description {
                    type string;
                    description "*";
                }
                leaf pd-function {
                    type boolean;
                    description "Whether the client 
                    can act as a requesting router 
                    to request prefixes using prefix 
                    delegation ([RFC3633]).";
                    mandatory true;
                }
                leaf rapid-commit {
                    type boolean;
                    description "'1' indicates a client 
                    can initiate a Solicit-Reply message 
                    exchange by adding a Rapid Commit 
                    option in Solicit message. '0' means 
                    the client is not allowed to add a 
                    Rapid Commit option to request 
                    addresses in a two-message 
                    exchange pattern.";
                    mandatory true;
                }
                container mo-tab {
                    description "The management tab 
                    label indicates the operation 
                    mode of the DHCPv6 client. 'm'=1 
                    and 'o'=1 indicate the client 
                    will use DHCPv6 to obtain all 
                    the configuration data. 'm'=1 
                    and 'o'=0 are a meaningless 
                    combination. 'm'=0 and 'o'=1 
                    indicate the client will use 
                    stateless DHCPv6 to obtain 
                    configuration data apart from 
                    addresses/prefixes data. 
                    'm'=0 and 'o'=0 represent the 
                    client will not use DHCPv6 
                    but use SLAAC to achieve 
                    configuration.";
                    leaf m-tab {
                        type boolean;
                        mandatory true;
                        description "*";
                    }
                    leaf o-tab {
                        type boolean;
                        mandatory true;
                        description "*";
                    }
                }
                container oro-options {
                    description "*";
                    list oro-option {
                        key option-code;
                        description "*";
                        leaf option-code {
                            type uint16;
                            mandatory true;
                            description "*";
                        }
                        leaf description {
                            type string;
                            mandatory true;
                            description "*";
                        }
                    }
                }
                container client-configured-options {
                    description "*";
                    list new-cli-option {
                        key option-code;
                        description "*";
                        leaf option-code {
                            type uint16;
                            manadatory true;
                            description "*";
                        }
                        leaf option-name {
                            type string;
                            manadatory true;
                            description "*";
                        }
                        leaf option-description {
                            type string;
                            manadatory true;
                            description "*";
                        }
                        leaf option-reference {
                            type string;
                            description "*";
                        }
                        leaf option-value {
                            type string;
                            manadatory true;
                            description "*";
                        }
                    }
                    container user-class-option {
                        description "*";
                        leaf enable {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        list user-class {
                            key user-class-id;
                            description "*";
                            leaf user-class-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf user-class-info {
                                type string;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                    container vendor-class-option {
                        description "*";
                        leaf enable {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        leaf ent-num {
                            type uint32;
                            mandatory true;
                            description "*";
                        }
                        leaf-list data {
                            type string;
                            description "*";
                        }
                    }
                    container client-fqdn-option {
                        description "*";
                        leaf enable {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        leaf fqdn {
                            type string;
                            mandatory true;
                            description "*";
                        }
                        leaf server-initiate-update {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        leaf client-initiate-update {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                    }
                    container client-architecture-type-option {
                        description "*";
                        leaf enable {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        list architecture-types {
                            key type-id;
                            description "*";
                            leaf type-id {
                                type uint16;
                                mandatory true;
                                description "*";
                            }
                            leaf most-preferred {
                                type boolean;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                    container client-network-interface-option {
                        description "*";
                        leaf enable {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        leaf type {
                            type uint8;
                            mandatory true;
                            description "*";
                        }
                        leaf major {
                            type uint8;
                            mandatory true;
                            description "*";
                        }
                        leaf minor {
                            type uint8;
                            mandatory true;
                            description "*";
                        }
                    }
                    container kerberos-principal-name-option {
                        description "*";
                        leaf enable {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        leaf principal-name {
                            type string;
                            mandatory true;
                            description "*";
                        }
                    }
                    container client-link-layer-addr-option {
                        description "*";
                        leaf enable {
                            type boolean;
                            mandatory true;
                            description "*";
                        }
                        leaf link-layer-type {
                            type uint16;
                            mandatory true;
                            description "*";
                        }
                        leaf link-layer-addr {
                            type string;
                            mandatory true;
                            description "*";
                        }
                    }
                }
                container identity-associations {
                    config "false";
                    description "IA is a construct through 
                    which a server and a client can identify, 
                    group, and manage a set of related IPv6 
                    addresses. The key of the list is a 
                    4-byte number IAID defined in [RFC3315].";
                    list identity-association {
                        key iaid;
                        description "*";
                        leaf iaid {
                            type uint32;
                            mandatory true;
                            description "*";
                        }
                        leaf ia-type {
                            type string;
                            mandatory true;
                            description "*";
                        }
                        leaf-list ipv6-addr {
                            type inet:ipv6-address;
                            description "*";
                        }
                        leaf-list ipv6-prefix {
                            type inet:ipv6-prefix;
                            description "*";
                        }
                        leaf-list prefix-length {
                            type uint8;
                            description "*";
                        }
                        leaf t1-time {
                            type yang:date-and-time;
                            mandatory true;
                            description "*";
                        }
                        leaf t2-time {
                            type yang:date-and-time;
                            mandatory true;
                            description "*";
                        }
                        leaf preferred-lifetime {
                            type yang:timeticks;
                            mandatory true;
                            description "*";
                        }
                        leaf valid-lifetime {
                            type yang:timeticks;
                            mandatory true;
                            description "*";
                        }
                    }
                }
                container if-other-paras {
                    config "false";
                    description "A client can obtain 
                    extra configuration data other than 
                    address and prefix information through 
                    DHCPv6. This container describes such 
                    data the client was configured. The 
                    potential configuration data may 
                    include DNS server addresses, SIP 
                    server domain names, etc.";
                    leaf-list uni-dhcpv6-serv-addr {
                        type inet:ipv6-address;
                        description "*";
                    }
                    container dns-paras {
                        description "*";
                        leaf domain-search-list {
                            type string;
                            mandatory true;
                            description "*";
                        }
                        list dns-servers {
                            key dns-serv-id;
                            description "*";
                            leaf dns-serv-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf dns-serv-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                    container sip-paras {
                        description "*";
                        list sip-servers {
                            key sip-serv-id;
                            description "*";
                            leaf sip-serv-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf sip-serv-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";
                            }
                            leaf sip-serv-domain-name {
                                type string;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                    container nis-paras {
                        description "*";
                        leaf nis-domain-name {
                            type string;
                            mandatory true;
                            description "*";
                        }
                        list nis-server {
                            key nis-serv-id;
                            description "*";
                            leaf nis-serv-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf nis-serv-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                    container nis-plus-paras {
                        description "*";
                        leaf nis-plus-domain-name {
                            type string;
                            mandatory true;
                            description "*";
                        }
                        list nis-plus-server {
                            key nis-plus-serv-id;
                            description "*";
                            leaf nis-plus-serv-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf nis-plus-serv-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                    leaf info-refresh-time {
                        type yang:timeticks;
                        description "*";
                    }
                    container time-zone-paras {
                        description "*";
                        leaf tz-posix {
                            type string;
                            mandatory true;
                            description "*";
                        }
                        leaf tz-database {
                            type string;
                            mandatory true;
                            description "*";
                        }
                    }
                    leaf cli-fqdn {
                        type string;
                        description "*";
                    }
                    container ntp-paras {
                        description "*";
                        list ntp-server {
                            key ntp-serv-id;
                            description "*";
                            leaf ntp-serv-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf ntp-serv-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";
                            }
                            leaf ntp-serv-mul-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";
                            }
                            leaf ntp-serv-fqdn {
                                type string;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                    container sntp-paras {
                        description "*";
                        list sntp-server {
                            key sntp-serv-id;
                            description "*";
                            leaf sntp-serv-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf sntp-serv-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";
                            }
                        }
                    }
                    container network-boot-paras {
                        description "*";
                        list boot-file {
                            key boot-file-id;
                            description "*";
                            leaf boot-file-id {
                                type uint8;
                                mandatory true;
                                description "*";
                            }
                            leaf-list suitable-arch-type {
                                type uint16;
                                description "*";
                            }
                            leaf-list suitable-net-if {
                                type uint32;
                                description "*";
                            }
                            leaf boot-file-url {
                                type string;
                                mandatory true;
                                description "*";
                            }
                            list boot-file-paras {
                                key para-id;
                                description "*";
                                leaf para-id {
                                    type uint8;
                                    mandatory true;
                                    description "*";
                                }
                                leaf parameter {
                                    type string;
                                    mandatory true;
                                    description "*";
                                }
                            }
                        }
                    }
                    container kerberos-paras {
                        description "*";
                        leaf default-realm-name {
                            type string;
                            mandatory true
                            description "*";							
                        }
                        list kdc-info {
                            key kdc-id;
                            description "*";
                            leaf kdc-id {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf priority {
                                type uint16;
                                mandatory true;
                                description "*";								
                            }
                            leaf weight {
                                type uint16;
                                mandatory true;
                                description "*";								
                            }
                            leaf transport-type {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf port-number {
                                type uint16;
                                mandatory true;
                                description "*";								
                            }
                            leaf kdc-ipv6-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";								
                            }
                            leaf realm-name {
                                type string;
                                mandatory true;
                                description "*";								
                            }
                        }
                    }                    
                    container addr-selection-paras {
                        description "*";
                        leaf automatic-row-add {
                            type boolean;
                            mandatory true;	
                            description "*";							
                        }
                        leaf prefer-temporary-addr {
                            type boolean;
                            mandatory true;
                            description "*";							
                        }
                        list policy-table {
                            key policy-id;
                            description "*";
                            leaf policy-id {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf label {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf precedence {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf prefix-len {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf prefix {
                                type inet:ipv6-prefix;
                                mandatory true;
                                description "*";								
                            }
                        }
                    }                      
                    leaf sol-max-rt {
                        type yang:timeticks;
                        mandatory true;
                        description "*";						
                    }                    
                    leaf inf-max-rt {
                        type yang:timeticks;
                        mandatory true;
                        description "*";						
                    }                    
                    container pcp-server-paras {
                        description "*";
                        list pcp-server {
                            key pcp-serv-id;
                            description "*";
                            leaf pcp-serv-id {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf pcp-serv-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";								
                            }
                        }
                    }                    
                    container s46-rule-paras {
                        description "*";
                        list s46-rule {
                            key rule-id;
                            description "*";
                            leaf rule-id {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf rule-type {
                                type enumeration {
                                enum "BMR";
                                enum "FMR";
                                }
                                mandatory true;
                                description "*";								
                            }
                            leaf ea-len {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf prefix4-len {
                                type uint8;
                                mandatory true;	
                                description "*";								
                            }
                            leaf ipv4-prefix {
                                type inet:ipv4-prefix;
                                mandatory true;
                                description "*";								
                            }
                            leaf prefix6-len {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf ipv6-prefix {
                                type inet:ipv6-prefix;
                                mandatory true;
                                description "*";								
                            }
                            uses portset-para;
                        }
                    }                    
                    container s46-br-paras {
                        description "*";
                        list br {
                            key br-id;
                            description "*";
                            leaf br-id {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf br-ipv6-addr {
                                type inet:ipv6-address;
                                mandatory true;
                                description "*";								
                            }
                        }
                    }                    
                    container s46-dmr-paras {
                        description "*";
                        list dmr {
                            key dmr-id;
                            description "*";
                            leaf dmr-id {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf dmr-prefix-len {
                                type uint8;
                                mandatory true;
                                description "*";								
                            }
                            leaf dmr-ipv6-prefix {
                                type inet:ipv6-prefix;
                                mandatory true;
                                description "*";								
                            }
                        }
                    }                    
                    container s46-v4-v6-binding-paras {
                        description "*";
                        leaf ipv4-addr {
                            type inet:ipv4-address;
                            mandatory true;
                            description "*";							
                        }
                        leaf bind-prefix6-len {
                            type uint8;
                            mandatory true;
                            description "*";							
                        }
                        uses portset-para;
                        leaf erp-local-domain-name {
                            type string;
                            mandatory true;
                            description "*";							
                        }
                    }                    
                    container supported-options {
                        description "*";
                        list supported-option {
                            key option-code;
                            description "*";
                            leaf option-code {
                                type uint16;
                                mandatory true;
                                description "*";								
                            }
                            leaf description {
                                type string;
                                mandatory true;
                                description "*";								
                            }
                        }
                    }
                }
                container packet-stats {
                    config "false";
                    description "A container records 
                    all the packet status information 
                    of a specific interface.";
                    leaf solicit-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf request-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf renew-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf rebind-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf decline-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf release-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf info-req-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf advertise-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf confirm-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf reply-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                    leaf reconfigure-count {
                        type uint32;
                        mandatory true;
                        description "*";
                    }
                }
            }
        }
    }
    
/*
 * Notifications
 */

    notification notifications {
        container dhcpv6-server-event {
            if-feature dhcpv6-server;
            description "server portion"; 
            container pool-running-out {
                description "raised when the address/prefix pool is going to
                run out.  A threshold for utilization ratio of the pool has been
                defined in the server feature so that it will notify the
                administrator when the utilization ratio reaches the threshold,
                and such threshold is a settable parameter";
                leaf utilization-ratio {
                    type uint16;
                    mandatory true;
                    description "*";
                }
                leaf duid {
                    type duidtype;
                    mandatory true;
                    description "DHCP Unique 
                    Identifer";
                }
                leaf serv-name {
                    type string;
                    description "*";
                }
                leaf pool-name {
                    type string;
                    mandatory true;
                    description "*";
                }
            }
            container invalid-client-detected {
                description "raised when the server has found a client
                which can be regarded as a potential attacker.  Some 
                description could also be included.";
                leaf duid {
                    type duidtype;
                    mandatory true;
                    description "DHCP Unique 
                    Identifer";
                }
                leaf description {
                    type string;
                    description "*";
                }
            }
        }
        container dhcpv6-relay-event {
            if-feature dhcpv6-relay;
            description "relay portion";
            container topo-changed {
                description "raised when the topology 
                of the relay agent is changed.";
                leaf relay-if-name {
                    type string;
                    mandatory true;
                    description "*";
                }
                leaf first-hop {
                    type boolean;
                    mandatory true;
                    description "*";
                }
                leaf last-entity-addr {
                    type inet:ipv6-address;
                    mandatory true;
                    description "*";
                }
            }
        }
        container dhcpv6-client-event {
            if-feature dhcpv6-client;
            description "client portion";
            container ia-lease-event {
                description "raised when the 
                client was allocated a new IA from 
                the server or it renew/rebind/release 
                its current IA";
                leaf event-type {
                    type enumeration{
                    enum "allocation";
                    enum "rebind";
                    enum "renew";
                    enum "release";
                    }
                    mandatory true;
                    description "*";
                }
                leaf duid {
                    type duidtype;
                    mandatory true;
                    description "DHCP Unique 
                    Identifer";
                }
                leaf iaid {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf serv-name {
                    type string;
                    description "*";
                }
                leaf description {
                    type string;
                    description "*";
                }
            }
            container invalid-ia-detected {
                description "raised when the identity 
                association of the client can be proved 
                to be invalid.  Possible condition includes 
                duplicated address, illegal address, etc.";
                leaf duid {
                    type duidtype;
                    mandatory true;
                    description "DHCP Unique 
                    Identifer";
                }
                leaf cli-duid {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf iaid {
                    type uint32;
                    mandatory true;
                    description "*";
                }
                leaf serv-name {
                    type string;
                    description "*";
                }
                leaf description {
                    type string;
                    description "*";
                }
            }
            container retransmission-failed {
                description "raised when the retransmission 
                mechanism defined in [RFC3315] is failed.";
                uses duid-para;
                leaf description {
                    type enumeration {
                        enum "MRC failed";
                        enum "MRD failed";
                    }
                    mandatory true;
                    description "*";
                }
            }
            container failed-status-turn-up {
                description "raised when the client receives 
                a message includes an unsuccessful Status Code 
                option.";
                leaf duid {
                    type duidtype;
                    mandatory true;
                    description "DHCP Unique 
                    Identifer";
                }
                leaf status-code {
                    type enumeration {
                        enum "1" {
                            description "UnspecFail";
                        }
                        enum "2" {
                            description "NoAddrAvail";
                        }
                        enum "3" {
                            description "NoBinding";
                        }
                        enum "4" {
                            description "NotOnLink";
                        }
                        enum "5" {
                            description "UseMulticast";
                        }
                    }
                    mandatory true;
                    description "*";
                }
            }
        }
    }
}
<CODE ENDS>
        ]]></artwork>
      </figure>
    </section>

    <section anchor="security" title="Security Considerations (TBD)">
      <t>TBD</t>
    </section>

    <section anchor="iana" title="IANA Considerations (TBD)">
      <t>TBD</t>
    </section>

    <section anchor="acknowledgements" title="Acknowledgements">
      <t>The authors would like to thank Qi Sun, Lishan Li and 
      Sladjana Zoric for their valuable contributions 
      to this work.</t>
    </section>
  </middle>

  <back>
    <references title="Normative References">
      <?rfc include='reference.RFC.2119'?>
      <?rfc include='reference.RFC.3315'?>
      <?rfc include='reference.RFC.3633'?>
      <?rfc include='reference.RFC.6020'?>
      <?rfc include='reference.RFC.6087'?>
      <?rfc include='reference.RFC.6991'?>
    </references>
    <references title="Informative References">
      <?rfc include='reference.RFC.3319'?>
      <?rfc include='reference.RFC.3646'?>
      <?rfc include='reference.RFC.3898'?>
      <?rfc include='reference.RFC.4242'?>
      <?rfc include='reference.RFC.4704'?>
      <?rfc include='reference.RFC.4833'?>
      <?rfc include='reference.RFC.5908'?>
      <?rfc include='reference.RFC.5970'?>
      <?rfc include='reference.RFC.4075'?>
      <?rfc include='reference.RFC.6334'?>
      <?rfc include='reference.RFC.6422'?>
      <?rfc include='reference.RFC.6440'?>
      <?rfc include='reference.RFC.6784'?>
      <?rfc include='reference.RFC.6939'?>
      <?rfc include='reference.RFC.7078'?>
      <?rfc include='reference.RFC.7083'?>
      <?rfc include='reference.RFC.7291'?>
      <?rfc include='reference.RFC.7598'?>

    </references>


  </back>
</rfc>

PAFTECH AB 2003-20262026-04-24 09:49:18