One document matched: draft-ietf-netmod-routing-cfg-00.xml
<?xml version="1.0"?>
<?rfc toc="yes"?>
<?rfc symrefs="yes"?>
<?rfc sortrefs="yes"?>
<rfc ipr="trust200902" category="std"
docName="draft-ietf-netmod-routing-cfg-00">
<front>
<title abbrev="YANG Routing Configuration">A YANG Data Model for
Routing Configuration</title>
<author initials="L." surname="Lhotka" fullname="Ladislav Lhotka">
<organization>CESNET</organization>
<address>
<email>lhotka@cesnet.cz</email>
</address>
</author>
<date day="27" month="April" year="2011"/>
<area>Operations and Management</area>
<workgroup>NETMOD</workgroup>
<abstract>
<t>This document contains a specification of two YANG modules that
together provide a data model for essential configuration of a
routing subsystem. It is expected that this module will serve as a
basis for further development of data models for individual
routing protocols and other related functions. The present data
model defines the building blocks for such configurations -
routing processes, routes and routing tables, routing protocol
instances and route filters.</t>
</abstract>
</front>
<middle>
<section anchor="sec.introduction" title="Introduction">
<t>This document contains an initial specification of two YANG
modules, "ietf-routing" and "ietf-ipv4-unicast-routing", that
together define the so-called core routing data model. This data
model will serve as a basis for the development of data models for
more sophisticated routing configurations. While these two modules
can be directly used for simple IPv4-only devices with static
routing, their main purpose is to provide basic building blocks
for more complicated setups involving other address families such
as IPv6, multiple routing protocols, and advanced functions, for
example route filtering and policy routing. To this end, it is
expected that this module will be augmented by numerous modules
developed by other IETF working groups.</t>
</section>
<section anchor="sec.term-not" title="Terminology and Notation">
<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"/>.</t>
<t>The following terms are defined in <xref target="RFC4741"/>:
<list style="symbols">
<t>client</t>
<t>message</t>
<t>operation</t>
<t>server</t>
</list></t>
<t>The following terms are defined in <xref target="RFC6020"/>:
<list style="symbols">
<t>augment</t>
<t>configuration data</t>
<t>container</t>
<t>data model</t>
<t>data node</t>
<t>data type</t>
<t>identity</t>
<t>mandatory node</t>
<t>module</t>
<t>operational state data</t>
<t>prefix</t>
<t>RPC operation</t>
</list></t>
<section anchor="sec.new-terms" title="Glossary of New Terms">
<t><list style="symbols">
<t>active route: a route which is actually used for packet
forwarding. If there are multiple candidate routes with the
same destination prefix, then it is up to the routing
algorithm to select the active route.</t>
</list></t>
</section>
<section anchor="sec.prefixes" title="Prefixes in Data Node Names">
<t>In this document, names of data nodes are used mostly without
a prefix, as long as it is clear from the context in which YANG
module each name is defined. Otherwise, names are prefixed with
the standard prefixes associated with YANG modules, as shown in
<xref target="tab.prefixes"/>.</t>
<texttable anchor="tab.prefixes"
title="Prefixes and corresponding YANG modules">
<ttcol>Prefix</ttcol>
<ttcol>YANG module</ttcol>
<ttcol>Reference</ttcol>
<c>eth</c><c>ex-ethernet</c><c><xref target="YANG-IF"/></c>
<c>if</c><c>ietf-interfaces</c><c><xref target="YANG-IF"/></c>
<c>inet</c><c>ietf-inet-types</c><c><xref target="RFC6021"/></c>
<c>ip</c><c>ex-ip</c><c><xref target="YANG-IF"/></c>
<c>rip</c><c>example-rip</c><c><xref target="app.rip"/></c>
<c>rt</c><c>ietf-routing</c><c><xref target="sec.mod-rt"/></c>
<c>v4ur</c><c>ietf-ipv4-unicast-routing</c><c><xref target="sec.mod-v4ur"/></c>
<c>yang</c><c>ietf-yang-types</c><c><xref target="RFC6021"/></c>
</texttable>
</section>
</section>
<section anchor="sec.objectives" title="Objectives">
<t>The initial design of the core routing data model was driven by
the following main objectives:
<list style="symbols">
<t>The data model should be suitable for the common address
families, in particular IPv4 and IPv6, and for unicast and
multicast routing as well as Multiprotocol Label Switching (MPLS).</t>
<t>Simple routing setups, such as static routing, should be
configurable in a simple way, ideally without any need to develop
additional YANG modules.</t>
<t>On the other hand, the core routing framework must
allow for complicated setups involving multiple routing tables
and multiple routing protocols, as well as controlled
redistributions of routing information.</t>
<t>Device vendors will want to map the data models built on this
generic framework to their proprietary data models and
configuration interfaces. Therefore, the framework should be
flexible enough to facilitate such a mapping and accommodate
data models with different logic.</t>
</list>
</t>
</section>
<section anchor="sec.design"
title="The Design of the Core Routing Data Model">
<t>The core routing data model consists of two YANG modules. The
first module, "ietf-routing", is rather minimal and provides only
a top-level container ("routing") and a list of routing
processes. Each routing process represents an instance of a
(virtual) router with a separate forwarding table (FIB, forwarding
information base). For a given address family, specified by an
Address Family Identifier (AFI) <xref target="IANA-AFI"/> and
Subsequent Address Family Identifier (SAFI) <xref
target="IANA-SAFI"/>, several independent routing processes may be
configured.</t>
<t>The second YANG module, "ietf-ipv4-unicast-routing", provides a
data modeling framework for IPv4 unicast routing with several
essential components: routes, routing tables, routing protocol
instances, route filters and RPC operations. The following
subsections provide further details about these components.</t>
<t>By combining the components in various ways, and possibly
filling them with appropriate contents defined in other
modules, a broad range of routing setups can be covered.</t>
<figure anchor="fig.exsetup"
title="Example setup of the routing subsystem">
<artwork><![CDATA[
+------------+
| FIB |
+------------+
^
|
+---+
| F |
+---+
^
+--------+ |
| direct | +---+ +--------------+ +---+ +--------------+
| routes |--->| F |--->| |<---| F |<---| |
+--------+ +---+ | main | +---+ | additional |
| routing | | routing |
+--------+ +---+ | table | +---+ | table |
| static |--->| F |--->| |--->| F |--->| |
| routes | +---+ +--------------+ +---+ +--------------+
+--------+ ^ | ^ |
| v | v
+---+ +---+ +---+ +---+
| F | | F | | F | | F |
+---+ +---+ +---+ +---+
^ | ^ |
| v | v
+----------+ +----------+
| routing | | routing |
| protocol | | protocol |
+----------+ +----------+
]]></artwork>
</figure>
<t><xref target="fig.exsetup"/> shows an example of a more
complicated setup:
<list style="symbols">
<t>Along with the main routing table, which must always be
present, an additional routing table is defined.</t>
<t>Each routing protocol instance, including the "static" and
"direct" pseudo-protocol instances, is connected to exactly one
routing table with which it can exchange routes (in both
directions, except for the "static" and "direct"
pseudo-protocols).</t>
<t>Routing tables may also be connected to each other and
exchange routes in one or both directions.</t>
<t>The forwarding information base (FIB) is a special routing
table which must always be present. Typically, the FIB receives
the active routes from the main routing table and the operating
system kernel uses this information for packet forwarding.</t>
<t>Route exchanges along all connections may be controlled by
means of route filters, denoted by "F" in the figure.</t>
</list></t>
<section anchor="sec.route" title="Route">
<t>Routes are basic units of information in a routing
system. The "ietf-ipv4-unicast-routing" module defines only the
following minimal set of route attributes:
<list style="symbols">
<t>destination-prefix - IP prefix specifying the set of
destination addresses for which the route may be used. This
attribute is mandatory.</t>
<t>next-hop - IP address of the adjacent router or host to
which packets with destination addresses belonging to
destination-prefix should be sent.</t>
<t>outgoing-interface - network interface that should be used
for sending packets with destination addresses belonging to
destination-prefix.</t>
</list>
</t>
<t>The above list of route attributes is sufficient for a
simple static routing configuration. It is expected that future
modules defining routing protocols will add other route
attributes such as metrics or preferences.</t>
<t>Routes and their attributes are used in both configuration
data, for example as manually configured static routes, as well
as in operational state data, for example as entries in routing
tables.</t>
</section>
<section anchor="sec.rtables" title="Routing Tables">
<t>Routing tables are lists of routes complemented with
administrative data, namely:
<list style="symbols">
<t>source-protocol - name of the routing protocol from which
the route was originally obtained.</t>
<t>last-modified - date and time of last modification, or
installation, of the route.</t>
</list></t>
<t>In the core routing data model, the list of routes in routing
tables is represented as operational state data. Routing
protocol operations result in route additions, removals and
modifications. This also includes manipulations via the "static"
pseudo-protocol.</t>
<t>The "ietf-ipv4-unicast-routing" module requires that at least
the following two routing tables MUST be configured for each
routing process:
<list style="symbols">
<t>The "ipv4-unicast-fib" table is the forwarding information
base used by the operating system kernel for forwarding IPv4
unicast datagrams.</t>
<t>The "ipv4-unicast-main" table is the main routing table. By
default, all IPv4 unicast routing protocols exchange routes
with this table, and active routes from the
"ipv4-unicast-main" routing table are installed in the
"ipv4-unicast-fib" table and used for packet forwarding.</t>
</list>
Additional routing tables MAY be configured.</t>
<t>Every routing table MAY serve as a source of routes for other
routing tables. To achieve this, one or more recipient routing
tables MAY be specified in the configuration of the source
routing table. In addition, a route filter may be configured for
each recipient routing table, which selects and/or manipulates
the routes that are passed on between the source and recipient
routing table.</t>
</section>
<section anchor="sec.proto"
title="Routing Protocol Instances">
<t>The "ietf-ipv4-unicast-routing" module provides an open-ended
framework for defining multiple routing protocol instances. Each
of them is identified by a name, which is unique within a
routing process, and MUST be assigned a
type from a selection which includes all routing protocol types
supported by the server, such as RIP, OSPF or BGP.</t>
<t>Each routing protocol instance is connected to exactly one
routing table. By default, every routing protocol instance is
connected to the main routing table, but any routing protocol
instance can be configured to use a different routing table,
provided such an extra table is configured.</t>
<t>Routes learned from the network by a routing protocol
instance are passed to the connected routing table and vice
versa - routes appearing in a routing table are passed to all
routing protocol connected to the table and advertised by that
protocol to the network.</t>
<t>Two independent route filters (see <xref
target="sec.filters"/>) may be defined for a routing protocol
instance to control the exchange of routes in both directions
between the routing protocol instance and the connected routing
table:
<list style="symbols">
<t>import filter controls which routes are passed from a
routing protocol instance to the routing table,</t>
<t>export filter controls which routes the routing protocol
instance may receive from the connected routing table.</t>
</list>
Note that, for historical reasons, the terms import and export
are used from the viewpoint of a routing table.</t>
<t>The "ietf-ipv4-unicast-routing" module defines two special
routing protocols - "direct" and "static". Both are in fact
pseudo-protocols, which means that they are confined to the
local device and do not exchange any routing information with
neighboring routers. Routes from both "direct" and "static"
protocol instances are passed to the connected routing table
(subject to route filters, if any), but an exchange in the
opposite direction is not allowed.</t>
<t>Every routing process MUST contain exactly one instance of
the "direct" pseudo-protocol. It is the source of routes to
directly connected networks (so-called direct routes). Such
routes are supplied by the operating system kernel based on the
detected and configured network interfaces, and they usually
appear in the main routing table. However, using the framework
defined in this document, the target routing table for direct
routes can be changed by connecting the "direct" protocol
instance to a non-default routing table, and the direct routes
can also be filtered before they appear in the routing
table.</t>
<t>The "static" routing pseudo-protocol allows for specifying
routes manually. It can be configured in zero or more instances,
although typically one instance suffices.</t>
<section anchor="sec.newproto"
title="Defining New Routing Protocols">
<t>It is expected that future YANG modules will create data
models for additional routing protocol types. In order to do
so, the new module has to define the protocol-specific
information and fit it to the core routing framework in the
following way:
<list style="symbols">
<t>A new identity MUST be defined for the routing protocol
and its base identity set to "rt:routing-protocol", or to an
identity derived from "rt:routing-protocol".</t>
<t>Additional route attributes MAY be defined. Their
definitions have to be inserted as operational state data by
augmenting the definition of "v4ur:route" inside
"v4ur:routing-table". Naturally, route attributes (including
the extra attributes) may be used in configuration data,
too, as demonstrated by the "static" pseudo-protocol.</t>
<t>The recommended way of defining configuration data
specific to the new protocol is to augment the
"routing-protocol-instance" list entry with a container that
encapsulates the configuration hierarchy of the new
protocol. The "augment" statement SHOULD be made conditional
by using a "when" substatement requiring that the new nodes
be used only if the "type" leaf node is equal to the new
protocol's identity.</t>
</list></t>
<t>The above steps are implemented by the example YANG module
for the RIP routing protocol in <xref
target="app.rip"/>. First, the module defines a new
identity for the RIP protocol:</t>
<figure>
<artwork><![CDATA[
identity rip {
base rt:routing-protocol;
description "Identity for the RIP routing protocol.";
}]]></artwork>
</figure>
<t>Second, new route attributes specific for the RIP protocol
("metric" and "tag") are added:</t>
<figure>
<artwork><![CDATA[
augment "/rt:routing/rt:routing-process/v4ur:ipv4-unicast-routing/"
+ "v4ur:routing-tables/v4ur:routing-table/"
+ "v4ur:routes/v4ur:route" {
when "../../../../v4ur:routing-protocol-instances/"
+ "v4ur:routing-protocol-instance[rt:name="
+ "current()/v4ur:source-protocol]/v4ur:type='rip:rip'";
description
"RIP-specific route components.";
leaf metric { ... }
leaf tag { ... }
}]]></artwork>
</figure>
<t>The "when" statement is used to make sure that the new
route attributes are only valid when the source protocol is
RIP.</t>
<t>Finally, RIP-specific configuration data are integrated
into the "v4ur:routing-protocol-instance" node by using the
following "augment" statement, which applies only to routing
protocol instances whose type is "rip:rip", and which is a part
of a routing process whose address family is "ipV4" and
subsequent address family identifier is "nlri-unicast":</t>
<figure>
<artwork><![CDATA[
augment "/rt:routing/rt:routing-process/v4ur:ipv4-unicast-routing/"
+ "v4ur:routing-protocol-instances/"
+ "v4ur:routing-protocol-instance" {
when "v4ur:type = 'rip:rip' and ../../../rt:address-family = 'ipV4'"
+ " and ../../../safi = 'nlri-unicast'";
container rip-configuration {
...
}
}]]></artwork>
</figure>
</section>
</section>
<section anchor="sec.filters" title="Route Filters">
<t>The "ietf-ipv4-unicast-routing" module provides a skeleton
for defining route filters that can be used to restrict the set
of routes being exchanged between a routing protocol instance
and a routing table, or between a source and a recipient routing
table. Route filters may also manipulate routes, i.e., add,
delete, or modify their properties.</t>
<t>By itself, the route filtering framework defined in the
"ietf-ipv4-unicast-routing" module allows to establish only the
two extreme routing policies in which either all routes are
allowed or all routes are denied. It is expected that a real
route filtering framework (or several alternative frameworks)
will be developed separately.</t>
<t>Each route filter is identified by a name which is unique
within a routing process. Its type
MUST be specified by the "type" identity reference - this opens
the space for multiple route filtering framework
implementations. The default value for route filter type is the
identity "deny-all-route-filter" defined in the "ietf-routing"
module, which represents the "deny all" route filtering
policy.</t>
</section>
<section anchor="sec.rpcs" title="RPC Operations">
<t>The "ietf-ipv4-unicast-routing-module" defines two RPC
operations:
<list style="symbols">
<t>"delete-route" operations allows the client to immediately
delete specific route(s) from a routing table within a routing
process. The first input parameter of this operation is the
name of the routing process, the second parameter is the
routing table to act upon, and the third (optional) parameter
is the "route" container with zero or more of the following
route attributes: "destination-prefix", "next-hop" and
"outgoing-interface". All routes that match these attributes
MUST be deleted from the selected routing table. If the
"route" container is missing or empty, all routes from the
selected routing table MUST be deleted.</t>
<t>"get-route" is used for querying the forwarding information
base of a routing process. The first input parameter is the
name of a routing process whose FIB is to be queried, and the
second parameter is an IPv4 destination address. The server
replies with an active route which is used for forwarding
datagrams to the destination address within the selected
routing process.</t>
</list></t>
</section>
</section>
<section anchor="sec.mod-rt"
title="Routing YANG Module">
<figure>
<artwork><![CDATA[<CODE BEGINS> file "ietf-routing@2011-04-27.yang"
module ietf-routing {
namespace "urn:ietf:params:xml:ns:yang:ietf-routing";
prefix rt;
organization
"IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
WG Chair: David Kessens
<mailto:david.kessens@nsn.com>
WG Chair: Juergen Schoenwaelder
<mailto:j.schoenwaelder@jacobs-university.de>
Editor: Ladislav Lhotka
<mailto:lhotka@cesnet.cz>";
description
"This module contains YANG definitions for top-level containers
for the configuration of routing together with several type
definitions and identities.";
revision 2011-04-27 {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Data Model for Routing Configuration";
}
/* Identities */
identity routing-protocol {
description
"Base identity from which routing protocol identities are
derived.";
}
identity direct {
base routing-protocol;
description
"Identity for the pseudo-protocol providing routes to directly
connected networks. An implementation MUST preconfigure
exactly one instance of this pseudo-protocol for each routing
process."; }
identity static {
base routing-protocol;
description
"Identity for static routing pseudo-protocol.";
}
identity route-filter {
description
"Base identity from which all route filters are
derived.";
}
identity deny-all-route-filter {
base route-filter;
description
"This identity represents a route filter that blocks all
routes.";
}
/* Type definitions */
typedef address-family {
type enumeration {
enum "other" {
value 0;
description
"none of the following";
}
enum "ipV4" {
value 1;
description
"IP Version 4";
}
enum "ipV6" {
value 2;
description
"IP Version 6";
}
enum "nsap" {
value 3;
description
"NSAP";
}
enum "hdlc" {
value 4;
description
"(8-bit multidrop)";
}
enum "bbn1822" {
value 5;
description
"BBN Report 1822";
}
enum "all802" {
value 6;
description
"(includes all 802 media plus Ethernet 'canonical
format')";
}
enum "e163" {
value 7;
}
enum "e164" {
value 8;
description
"(SMDS, FrameRelay, ATM)";
}
enum "f69" {
value 9;
description
"(Telex)";
}
enum "x121" {
value 10;
description
"(X.25, Frame Relay)";
}
enum "ipx" {
value 11;
description
"IPX (Internet Protocol Exchange)";
}
enum "appleTalk" {
value 12;
description
"Apple Talk";
}
enum "decnetIV" {
value 13;
description
"DEC Net Phase IV";
}
enum "banyanVines" {
value 14;
description
"Banyan Vines";
}
enum "e164withNsap" {
value 15;
description
"(E.164 with NSAP format subaddress)";
}
enum "dns" {
value 16;
description
"(Domain Name System)";
}
enum "distinguishedName" {
value 17;
description
"(Distinguished Name, per X.500)";
}
enum "asNumber" {
value 18;
description
"(16-bit quantity, per the AS number space)";
}
enum "xtpOverIPv4" {
value 19;
description
"XTP over IP version 4";
}
enum "xtpOverIpv6" {
value 20;
description
"XTP over IP version 6";
}
enum "xtpNativeModeXTP" {
value 21;
description
"XTP native mode XTP";
}
enum "fibreChannelWWPN" {
value 22;
description
"Fibre Channel World-Wide Port Name";
}
enum "fibreChannelWWNN" {
value 23;
description
"Fibre Channel World-Wide Node Name";
}
enum "gwid" {
value 24;
description
"Gateway Identifier";
}
enum "afi" {
value 25;
description
"AFI for L2VPN";
}
}
description
"This typedef is a YANG enumeration of IANA-registered
address families.";
reference
"http://www.iana.org/assignments/ianaaddressfamilynumbers-mib";
}
typedef subsequent-address-family {
type enumeration {
enum "nlri-unicast" {
value 1;
description
"Network Layer Reachability Information used for
unicast forwarding";
reference "RFC4760";
}
enum "nlri-multicast" {
value 2;
description
"Network Layer Reachability Information used for
multicast forwarding";
reference "RFC4760";
}
enum "nlri-mpls" {
value 4;
description
"Network Layer Reachability Information (NLRI) with
MPLS Labels";
reference "RFC3107";
}
enum "mcast-vpn" {
value 5;
description
"MCAST-VPN";
reference "draft-ietf-l3vpn-2547bis-mcast-bgp-08";
}
enum "nlri-dynamic-ms-pw" {
value 6;
status obsolete;
description
"Network Layer Reachability Information used for Dynamic
Placement of Multi-Segment Pseudowires (TEMPORARY -
Expires 2008-08-23)";
reference "draft-ietf-pwe3-dynamic-ms-pw-13";
}
enum "tunnel-safi" {
value 64;
description
"Tunnel SAFI";
reference "draft-nalawade-kapoor-tunnel-safi-05";
}
enum "vpls" {
value 65;
description
"Virtual Private LAN Service (VPLS)";
reference "RFC4761, RFC6074";
}
enum "bgp-mdt" {
value 66;
description
"BGP MDT SAFI";
reference "RFC6037";
}
enum "bgp-4over6" {
value 67;
description
"BGP 4over6 SAFI";
reference "RFC5747";
}
enum "bgp-6over4" {
value 68;
description
"BGP 6over4 SAFI";
reference "mailto:cuiyong&tsinghua.edu.cn";
}
enum "l1vpn-auto-discovery" {
value 69;
description
"Layer-1 VPN auto-discovery information";
reference "draft-ietf-l1vpn-bgp-auto-discovery-05";
}
enum "mpls-vpn" {
value 128;
description
"MPLS-labeled VPN address";
reference "RFC4364";
}
enum "multicast-bgp-mpls-vpn" {
value 129;
description
"Multicast for BGP/MPLS IP Virtual Private Networks
(VPNs)";
reference
"draft-ietf-l3vpn-2547bis-mcast-10,
draft-ietf-l3vpn-2547bis-mcast-10";
}
enum "route-target-constraints" {
value 132;
description
"Route Target constraints";
reference "RFC4684";
}
enum "ipv4-diss-flow" {
value 133;
description
"IPv4 dissemination of flow specification rules";
reference "RFC5575";
}
enum "vpnv4-diss-flow" {
value 134;
description
"IPv4 dissemination of flow specification rules";
reference "RFC5575";
}
enum "vpn-auto-discovery" {
value 140;
description
"VPN auto-discovery";
reference "draft-ietf-l3vpn-bgpvpn-auto-09";
}
}
description
"This typedef is a YANG enumeration of IANA-registered
subsequent address families.";
reference "http://www.iana.org/assignments/safi-namespace/"
+ "safi-namespace.xml";
}
typedef routing-process-ref {
type leafref {
path "/rt:routing/rt:routing-process/rt:name";
}
description
"This type is used for leafs that reference a routing
process.";
}
/* Data nodes */
container routing {
description
"Routing parameters.";
list routing-process {
key "name";
description
"Each entry is a container for configuration and operational
state data of a single (virtual) router for a given address
family and subsequent address family identifier (SAFI). Each
entry has a unique name.
The definitions of data for a particular address family and
subsequent address family shall be provided via augmentation
by other modules.";
leaf name {
type string;
description
"The unique name of the routing process.";
}
leaf address-family {
type address-family;
default "ipV4";
description
"Address family of the routing process.";
}
leaf safi {
type subsequent-address-family;
default "nlri-unicast";
description
"Subsequent address family identifier of the routing
process.";
}
leaf description {
type string;
description
"Textual description of the routing process.";
}
leaf enabled {
type boolean;
default "true";
description
"Enable or disable the routing process. The default value
is 'true', which means that the process is enabled.";
}
}
}
}
<CODE ENDS>]]></artwork>
</figure>
</section>
<section anchor="sec.mod-v4ur"
title="IPv4 Unicast Routing YANG Module">
<figure>
<artwork><![CDATA[<CODE BEGINS> file "ietf-ipv4-unicast-routing@2011-04-27.yang"
module ietf-ipv4-unicast-routing {
namespace "urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing";
prefix v4ur;
import ietf-routing {
prefix rt;
}
import ietf-yang-types {
prefix yang;
}
import ietf-inet-types {
prefix inet;
}
import ietf-interfaces {
prefix if;
}
organization
"IETF NETMOD (NETCONF Data Modeling Language) Working Group";
contact
"WG Web: <http://tools.ietf.org/wg/netmod/>
WG List: <mailto:netmod@ietf.org>
WG Chair: David Kessens
<mailto:david.kessens@nsn.com>
WG Chair: Juergen Schoenwaelder
<mailto:j.schoenwaelder@jacobs-university.de>
Editor: Ladislav Lhotka
<mailto:lhotka@cesnet.cz>";
description
"This module augments the 'ietf-routing' module with YANG
definitions for basic configuration of IPv4 unicast routing.
It is immediately usable for a device that needs just a single
routing table populated with static routes.
On the other hand, the framework is designed to handle
arbitrarily complex configurations with any number of routing
tables and various routing protocols (in multiple instances).";
revision 2011-04-27 {
description
"Initial revision.";
reference
"RFC XXXX: A YANG Data Model for Routing Configuration";
}
/* Groupings */
grouping routing-process-name {
leaf routing-process-name {
type rt:routing-process-ref;
must "/rt:routing/rt:routing-process[rt:name = current()]"
+ "/rt:address-family = 'ipV4' and "
+ "/rt:routing/rt:routing-process[rt:name = current()]"
+ "/rt:safi = 'nlri-unicast'" {
description
"The referred routing process must be IPv4 unicast.";
}
description "The name of a routing process.";
}
description
"This grouping defines the first common parameter of both
RPC operations below.";
}
/* RPC operations */
rpc get-route {
description
"Query the forwarding information base of an IPv4 unicast
routing process whose name is given as the first
parameter. The second parameter is an IPv4 destination
address. The server returns the route which is currently used
for forwarding datagrams to that destination address, or an
error message, if no such route exists.";
input {
uses routing-process-name;
leaf destination-address {
type inet:ipv4-address;
description
"Second parameter - IPv4 destination address.";
}
}
output {
container route {
description
"Contents of the reply.";
leaf destination-prefix {
type inet:ipv4-prefix;
mandatory true;
description
"Destination prefix of the returned route.";
}
leaf next-hop {
type inet:ipv4-address;
description
"Next hop address of the returned route.";
}
leaf outgoing-interface {
type if:interface-ref;
description
"Outgoing interface of the returned route.";
}
}
}
}
rpc delete-route {
description
"Delete all routes that match the given attributes from a
routing table within a routing process.
Parameters:
1. routing process name,
2. routing table name,
3. Container 'route' with route attributes.
<ok> is returned by the server upon successful completion.";
input {
uses routing-process-name;
leaf routing-table {
type leafref {
path "/rt:routing/rt:routing-process[rt:name=current()/../"
+ "routing-process-name]/ipv4-unicast-routing/"
+ "routing-tables/routing-table/name";
}
mandatory true;
description
"First parameter.";
}
container route {
description
"Second parameter. All routes matching the route
attributes must be deleted from the routing table.
If this container is empty or missing, all routes
from the selected routing table are deleted.";
leaf destination-prefix {
type inet:ipv4-prefix;
description
"Match destination prefix.";
}
leaf next-hop {
type inet:ipv4-address;
description
"Match next hop.";
}
leaf outgoing-interface {
type if:interface-ref;
description
"Match outgoing interface.";
}
}
}
}
/* Data nodes */
augment "/rt:routing/rt:routing-process" {
when "afi='ipV4' and safi='nlri-unicast'" {
description
"IPv4 unicast.";
}
description
"Definitions of data nodes that augment a routing process
for IPv4 unicast.";
container ipv4-unicast-routing {
description
"Container for IPv4 unicast routing configuration and
operational state data.";
container routing-protocol-instances {
description
"Container for the list of configured routing protocol
instances.";
list routing-protocol-instance {
key "name";
description
"An instance of a routing protocol.";
container static-routes {
when "../type='rt:static'" {
description
"These data nodes are only valid for the static
pseudo-protocol.";
}
description
"Configuration of a 'static' pseudo-protocol
instance consists of a list of routes.";
list static-route {
key "id";
ordered-by user;
description
"An user-ordered list of static routes.";
leaf id {
type string;
description
"An identification string for the route.";
}
leaf description {
type string;
description
"Textual description of the route.";
}
leaf destination-prefix {
type inet:ipv4-prefix;
mandatory true;
description
"The destination prefix for which the route may
be used.";
}
leaf next-hop {
type inet:ipv4-address;
description
"IPv4 address of the host or router to which
packets whose address matches 'destination-prefix'
are to be forwarded.";
}
leaf outgoing-interface {
type if:interface-ref;
description
"Name of the outgoing interface. This attribute
is mainly used in direct routes.";
}
}
}
leaf name {
type string;
description
"The name of the routing protocol instance.";
}
leaf description {
type string;
description
"Textual description of the routing protocol
instance.";
}
leaf type {
type identityref {
base rt:routing-protocol;
}
mandatory true;
description
"Type of the routing protocol - an identity derived
from the 'rt:routing-protocol' base identity.";
}
leaf routing-table {
type leafref {
path "../../../routing-tables/routing-table/name";
}
default "ipv4-unicast-main";
description
"The routing table to which the routing protocol
instance is connected. By default it is the
'ipv4-unicast-main' table.";
}
leaf import-filter {
type leafref {
path "../../../route-filters/route-filter/name";
}
description
"Reference to a route filter that is used for
filtering routes passed from this routing protocol
instance to the routing table specified by the
'routing-table' sibling node. If this leaf is not
present, the behavior is protocol-specific, but
typically it means that all routes are accepted.";
}
leaf export-filter {
type leafref {
path "../../../route-filters/route-filter/name";
}
description
"Reference to a route filter that is used for filtering
routes passed from the routing table specified by the
'routing-table' sibling to this routing protocol
instance. If this leaf is not present, the behavior is
protocol-specific - typically it means that all routes
are accepted, except for the 'direct' and 'static'
pseudo-protocols which accept no routes from any
routing table.";
}
}
}
container route-filters {
description
"Container for configured route filters.";
list route-filter {
key "name";
description
"Route filters are used for filtering and/or manipulating
routes that are passed between a routing protocol and a
routing table or vice versa, or between two routing
tables. It is expected that other modules augment this
list with contents specific for a particular route
filter type.";
leaf name {
type string;
description
"The name of the route filter.";
}
leaf description {
type string;
description
"Textual description of the route filter.";
}
leaf type {
type identityref {
base rt:route-filter;
}
default "rt:deny-all-route-filter";
description
"Type of the route-filter - an identity derived
from the 'rt:route-filter' base identity. The default
value represents an all-blocking filter.";
}
}
}
container routing-tables {
must "routing-table/name='ipv4-unicast-fib'" {
description
"IPv4 unicast forwarding information base.";
}
must "routing-table/name='ipv4-unicast-main'" {
description
"The main IPv4 unicast routing table.";
}
description
"Container for configured routing tables.";
list routing-table {
key "name";
description
"Each entry represents a configured routing table. At
least two entries with names 'ipv4-unicast-fib' and
'ipv4-unicast-main' must exist.";
container routes {
config false;
description
"Current contents of the routing table. Note that
it is operational state data.";
list route {
description
"A routing table entry.";
leaf destination-prefix {
type inet:ipv4-prefix;
description
"Destination prefix.";
}
leaf next-hop {
type inet:ipv4-address;
description
"IPv4 address of the next hop.";
}
leaf outgoing-interface {
type if:interface-ref;
description
"Name of the outgoing interface.";
}
leaf source-protocol {
type leafref {
path "../../../../../routing-protocol-instances/"
+ "routing-protocol-instance/name";
}
description
"Protocol instance from which the route comes.";
}
leaf last-modified {
type yang:date-and-time;
description
"Time stamp of the last modification of the
route. If the route was never modified, it is the
time when the route was inserted to the routing
table.";
}
}
}
leaf name {
type string;
description
"The name of the routing table.";
}
leaf description {
type string;
description
"Textual description of the routing table.";
}
list recipient-routing-tables {
key "recipient-name";
description
"A list of routing tables that receive routes from
the parent routing table.";
leaf recipient-name {
type leafref {
path "../../../routing-table/name";
}
description
"The name of the recipient routing table.";
}
leaf filter {
type leafref {
path "../../../../route-filters/route-filter/name";
}
description
"A route filter which is applied to the routes
passed on to the recipient routing table.";
}
}
}
}
}
}
}
<CODE ENDS>]]></artwork>
</figure>
</section>
<section anchor="sec.iana" title="IANA Considerations">
<t>This document registers the following two namespace URIs in the
IETF XML registry <xref target="RFC3688"/>:</t>
<figure>
<artwork>
----------------------------------------------------------
URI: urn:ietf:params:xml:ns:yang:ietf-routing
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
----------------------------------------------------------
----------------------------------------------------------
URI: urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing
Registrant Contact: The IESG.
XML: N/A, the requested URI is an XML namespace.
----------------------------------------------------------
</artwork>
</figure>
<t>This document registers two YANG modules in the YANG Module
Names registry <xref target="RFC6020"/>:</t>
<figure>
<artwork>
-------------------------------------------------------------------
name: ietf-routing
namespace: urn:ietf:params:xml:ns:yang:ietf-routing
prefix: rt
reference: RFC XXXX
-------------------------------------------------------------------
-------------------------------------------------------------------
name: ietf-ipv4-unicast-routing
namespace: urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing
prefix: v4ur
reference: RFC XXXX
-------------------------------------------------------------------
</artwork>
</figure>
</section>
<section anchor="sec-cons" title="Security Considerations">
<t>TBD.</t>
</section>
<section anchor="acknowledgments" title="Acknowledgments">
<t>The author wishes to thank Juergen Schoenwaelder and Martin
Bjorklund for their helpful comments and suggestions.</t>
</section>
</middle>
<back>
<references title="Normative References">
<reference anchor="IANA-AFI">
<front>
<title abbrev="AFI Numbers">Address Family Numbers.</title>
<author>
<organization>IANA</organization>
</author>
<date year="2011" month="January" day="20"/>
</front>
<format
type="HTML"
target="http://www.iana.org/assignments/address-family-numbers/address-family-numbers.xml"/>
</reference>
<reference anchor="IANA-SAFI">
<front>
<title abbrev="AFI Numbers">Subsequent Address Family
Identifiers (SAFI) Parameters.</title>
<author>
<organization>IANA</organization>
</author>
<date year="2011" month="March" day="04"/>
</front>
<format
type="HTML"
target="http://www.iana.org/assignments/safi-namespace/safi-namespace.xml"/>
</reference>
<reference anchor='RFC2119'>
<front>
<title abbrev='RFC Key Words'>Key words for use in RFCs to
Indicate Requirement Levels</title>
<author initials='S.' surname='Bradner' fullname='Scott Bradner'>
<organization/>
</author>
<date year='1997' month='March' />
</front>
<seriesInfo name='BCP' value='14' />
<seriesInfo name='RFC' value='2119' />
<format type='TXT' octets='4723'
target='ftp://ftp.isi.edu/in-notes/rfc2119.txt' />
</reference>
<reference anchor='RFC3688'>
<front>
<title>The IETF XML Registry</title>
<author initials='M.' surname='Mealling' fullname='M. Mealling'>
<organization/></author>
<date year='2004' month='January' />
</front>
<seriesInfo name='BCP' value='81' />
<seriesInfo name='RFC' value='3688' />
<format type='TXT' octets='17325'
target='ftp://ftp.isi.edu/in-notes/rfc3688.txt' />
</reference>
<reference anchor='RFC4741'>
<front>
<title>NETCONF Configuration Protocol</title>
<author initials='R.' surname='Enns' fullname='R. Enns'>
<organization /></author>
<date year='2006' month='December' />
</front>
<seriesInfo name='RFC' value='4741' />
<format type='TXT' octets='173914'
target='http://www.ietf.org/rfc/rfc4741.txt' />
</reference>
<reference anchor='RFC6020'>
<front>
<title>YANG - A Data Modeling Language for Network
Configuration Protocol (NETCONF)</title>
<author role="editor" initials='M' surname='Bjorklund'
fullname='Martin Bjorklund'>
<organization>Tail-f Systems</organization>
</author>
<date month='September' year='2010' />
</front>
<seriesInfo name='RFC' value='6020'/>
<format type='HTML'
target='http://tools.ietf.org/html/rfc6020' />
</reference>
<reference anchor='RFC6021'>
<front>
<title>Common YANG Data Types</title>
<author role="editor" initials='J.' surname='Schoenwaelder'
fullname='Juergen Schoenwaelder'>
<organization />
</author>
<date month='September' year='2010' />
</front>
<seriesInfo name='RFC'
value='6021' />
<format type='HTML'
target='http://tools.ietf.org/html/rfc6021'/>
</reference>
<reference anchor='YANG-IF'>
<front>
<title>A YANG Data Model for Interface Configuration</title>
<author initials='M' surname='Bjorklund'
fullname='Martin Bjorklund'>
<organization />
</author>
<date month='December' day='8' year='2010' />
</front>
<seriesInfo name='Internet-Draft'
value='draft-bjorklund-netmod-interfaces-cfg-00' />
<format type='HTML'
target='http://tools.ietf.org/html/draft-bjorklund-netmod-interfaces-cfg-00' />
</reference>
</references>
<references title="Informative References">
<reference anchor='RFC6087'>
<front>
<title>Guidelines for Authors and Reviewers of YANG Data Model
Documents</title>
<author initials='A.' surname='Bierman'
fullname='Andy Bierman'>
<organization />
</author>
<date month='January' year='2011' />
</front>
<seriesInfo name='RFC'
value='6087' />
<format type='HTML'
target='http://tools.ietf.org/html/rfc6087'/>
</reference>
</references>
<section anchor="app.rip"
title="Example - Adding a New Routing Protocol">
<t>This appendix demonstrates how the core routing data model can be
extended to support a new routing protocol. <xref
target="app.rip-yang"/> contains a YANG module which is used for
this purpose. It is intended only as an illustration and not as a
real definition of a data model for the RIP routing
protocol. Also, for the sake of brevity, we do not follow all the
guidelines specified in <xref target="RFC6087"/>.</t>
<t><xref target="app.rip-xml"/> then contains a complete instance
XML document - a reply to the NETCONF <get> message from a
server that uses the RIP protocol as well as static routing.</t>
<section anchor="app.rip-yang"
title="Example YANG Module for Routing Information
Protocol">
<figure>
<artwork>
<![CDATA[module example-rip {
namespace "http://example.com/rip";
prefix rip;
import ietf-interfaces {
prefix if;
}
import ietf-routing {
prefix rt;
}
identity rip {
base rt:routing-protocol;
description
"Identity for the RIP routing protocol.";
}
typedef rip-metric {
type uint8 {
range "0..16";
}
}
augment "/rt:routing/rt:routing-protocol-instances/" +
"rt:routing-protocol-instance" {
when "rt:type='rip:rip'";
container rip-configuration {
container rip-interfaces {
list rip-interface {
key "name";
leaf name {
type if:interface-ref;
}
leaf enabled {
type boolean;
default "true";
}
leaf metric {
type rip-metric;
default "1";
}
/* Additional per-interface RIP configuration */
}
}
leaf update-interval {
type uint8 {
range "10..60";
}
units "seconds";
default "30";
description
"Time interval between periodic updates.";
}
/* Additional RIP configuration */
}
}
augment "/rt:routing/rt:routing-tables/rt:routing-table/rt:route" {
when "../../../rt:routing-protocol-instances/" +
"rt:routing-protocol-instance[rt:name=" +
"current()/rt:source-protocol]/rt:type='rip:rip'";
description
"RIP-specific route components.";
leaf metric {
type rip-metric;
}
leaf tag {
type uint16;
default "0";
description
"This leaf may be used to carry additional info, e.g. AS
number.";
}
}
}
]]></artwork>
</figure>
</section>
<section anchor="app.rip-xml"
title="Sample Reply to the NETCONF <get> Message">
<t>This section contains a sample reply to the NETCONF
<get> message, which could be sent by a server supporting
(and advertizing in <hello>) the following YANG modules:
<list style="symbols">
<t>ietf-interfaces <xref target="YANG-IF"/>,</t>
<t>ex-ethernet <xref target="YANG-IF"/>,</t>
<t>ex-ip <xref target="YANG-IF"/>,</t>
<t>ietf-routing (<xref target="sec.mod-rt"/>),</t>
<t>ietf-ipv4-unicast-routing (<xref target="sec.mod-v4ur"/>),</t>
<t>example-rip (<xref target="app.rip-yang"/>).</t>
</list></t>
<t>We assume a simple network setup as shown in <xref
target="fig.exnet"/>: routers "ISP" and "A" use RIP for
exchanging routing information whereas static routing is used
in the private network. In order to avoid the redistribution of
the routes to the private subnetworks 192.168.1.0/24 and
192.168.2.0/24 in RIP, an export filter is used in the RIP protocol
configuration preventing the routes from the main routing table
from appearing in RIP updates.</t>
<figure anchor="fig.exnet"
title="Example network configuration">
<artwork><![CDATA[
+-----------------+
| |
| Router ISP |
| |
+--------+--------+
|192.0.2.2
|
|
eth0|192.0.2.1
+--------+--------+
| |
| Router A |
| |
+--------+--------+
eth1|192.168.1.1
|
|
|192.168.1.254
+--------+--------+
| |
| Router B |
| |
+--------+--------+
|192.168.2.1
|
]]>
</artwork>
</figure>
<t>Router "A" then could send the following XML document as its
reply to the NETCONF <get> message:</t>
<figure>
<artwork>
<![CDATA[<?xml version="1.0"?>
<nc:rpc-reply
message-id="101"
xmlns="urn:ietf:params:xml:ns:yang:ietf-ipv4-unicast-routing"
xmlns:nc="urn:ietf:params:xml:ns:netconf:base:1.0"
xmlns:if="urn:ietf:params:xml:ns:yang:ietf-interfaces"
xmlns:eth="http://example.com/ethernet"
xmlns:ip="http://example.com/ip"
xmlns:rt="urn:ietf:params:xml:ns:yang:ietf-routing"
xmlns:rip="http://example.com/rip">
<nc:data>
<if:interfaces>
<if:interface>
<if:name>eth0</if:name>
<if:type>ethernetCsmacd</if:type>
<if:location>05:00.0</if:location>
<ip:ip>
<ip:address>
<ip:ip>192.0.2.1</ip:ip>
<ip:prefix-length>24</ip:prefix-length>
</ip:address>
</ip:ip>
</if:interface>
<if:interface>
<if:name>eth1</if:name>
<if:type>ethernetCsmacd</if:type>
<if:location>05:00.1</if:location>
<ip:ip>
<ip:address>
<ip:ip>192.168.1.1</ip:ip>
<ip:prefix-length>24</ip:prefix-length>
</ip:address>
</ip:ip>
</if:interface>
</if:interfaces>
<rt:routing>
<rt:routing-process>
<rt:name>inet-0</rt:name>
<rt:address-family>ipV4</rt:address-family>
<rt:safi>nlri-unicast</rt:safi>
<ipv4-unicast-routing>
<routing-protocol-instances>
<routing-protocol-instance>
<name>direct</name>
<type>rt:direct</type>
</routing-protocol-instance>
<routing-protocol-instance>
<name>st0</name>
<description>
Static routing is used for the internal network.
</description>
<type>rt:static</type>
<static-routes>
<static-route>
<id>id-6378</id>
<destination-prefix>192.168.2.0/24</destination-prefix>
<next-hop>192.168.1.254</next-hop>
</static-route>
</static-routes>
</routing-protocol-instance>
<routing-protocol-instance>
<name>rip0</name>
<description>
RIP is used on the uplink.
Static routes to the internal networks are not
advertized in RIP.
</description>
<type>rip:rip</type>
<export-filter>deny-all</export-filter>
<rip:rip-configuration>
<rip:rip-interfaces>
<rip:rip-interface>
<rip:name>eth0</rip:name>
</rip:rip-interface>
</rip:rip-interfaces>
</rip:rip-configuration>
</routing-protocol-instance>
</routing-protocol-instances>
<route-filters>
<route-filter>
<name>deny-all</name>
</route-filter>
</route-filters>
<routing-tables>
<routing-table>
<name>ipv4-unicast-fib</name>
<routes>
<route>
<destination-prefix>192.0.2.1/24</destination-prefix>
<source-protocol>direct</source-protocol>
<outgoing-interface>eth0</outgoing-interface>
<last-modified>2010-04-01T17:11:27+01:00</last-modified>
</route>
<route>
<destination-prefix>192.168.1.0/24</destination-prefix>
<source-protocol>direct</source-protocol>
<outgoing-interface>eth1</outgoing-interface>
<last-modified>2010-04-01T17:11:27+01:00</last-modified>
</route>
<route>
<destination-prefix>192.168.2.0/24</destination-prefix>
<source-protocol>st0</source-protocol>
<next-hop>192.168.1.254</next-hop>
<last-modified>2010-04-01T17:11:32+01:00</last-modified>
</route>
<route>
<destination-prefix>0.0.0.0/0</destination-prefix>
<source-protocol>rip0</source-protocol>
<next-hop>192.168.1.254</next-hop>
<rip:metric>2</rip:metric>
<rip:tag>64500</rip:tag>
<last-modified>2010-04-01T18:02:45+01:00</last-modified>
</route>
</routes>
</routing-table>
<routing-table>
<name>ipv4-unicast-main</name>
<recipient-routing-tables>
<recipient-name>ipv4-unicast-fib</recipient-name>
</recipient-routing-tables>
<routes>
<route>
<destination-prefix>192.0.2.1/24</destination-prefix>
<source-protocol>direct</source-protocol>
<outgoing-interface>eth0</outgoing-interface>
<last-modified>2010-04-01T17:11:27+01:00</last-modified>
</route>
<route>
<destination-prefix>192.168.1.0/24</destination-prefix>
<source-protocol>direct</source-protocol>
<outgoing-interface>eth1</outgoing-interface>
<last-modified>2010-04-01T17:11:27+01:00</last-modified>
</route>
<route>
<destination-prefix>192.168.2.0/24</destination-prefix>
<source-protocol>st0</source-protocol>
<next-hop>192.168.1.254</next-hop>
<last-modified>2010-04-01T17:11:32+01:00</last-modified>
</route>
<route>
<destination-prefix>0.0.0.0/0</destination-prefix>
<source-protocol>rip0</source-protocol>
<next-hop>192.168.1.254</next-hop>
<rip:metric>2</rip:metric>
<rip:tag>64500</rip:tag>
<last-modified>2010-04-01T18:02:45+01:00</last-modified>
</route>
</routes>
</routing-table>
</routing-tables>
</ipv4-unicast-routing>
</rt:routing-process>
</rt:routing>
</nc:data>
</nc:rpc-reply>
]]></artwork>
</figure>
</section>
</section>
</back>
</rfc>
| PAFTECH AB 2003-2026 | 2026-04-23 10:57:46 |