One document matched: draft-ietf-ipngwg-tla-assignment-00.txt

INTERNET-DRAFT                              R. Hinden, Ipsilon Networks
July 16, 1997                                          M. O'Dell, UUNET




                      TLA and NLA Assignment Rules


               <draft-ietf-ipngwg-tla-assignment-00.txt>



Status of this Memo

   This document is an Internet Draft.  Internet Drafts are working
   documents of the Internet Engineering Task Force (IETF), its Areas,
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   This internet draft expires on January 17, 1998.


1.0 Introduction


   This document defines assignment rules for Top-Level Aggregation
   Identifiers (TLA ID) and Next-Level Aggregation Identifiers (NLA ID)
   as defined in [AGGR].  These rules apply to registries allocating TLA
   ID's and to organizations receiving TLA ID's.

   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 [RFC 2119].






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2.0 IPv6 Aggregatable Global Unicast Address Format

   This document defines assignment rules for the TLA ID and NLA ID
   fields in the IPv6 Aggregatable Global Unicast Address Format.  This
   address format is designed to support both the current provider-based
   aggregation and a new type of exchange-based aggregation.  The
   combination will allow efficient routing aggregation for sites that
   connect directly to providers and for sites that connect to
   exchanges.  Sites will have the choice to connect to either type of
   aggregation entity.

   While this address format is designed to support exchange-based
   aggregation (in addition to current provider-based aggregation) it is
   not dependent on exchanges for it's overall route aggregation
   properties.  It will provide efficient route aggregation with only
   provider-based aggregation.

   The aggregatable global unicast address format as defined in [AGGR]
   is as follows:

      | 3 |  13 |    32     |   16   |          64 bits               |
      +---+-----+-----------+--------+--------------------------------+
      |FP | TLA | NLA ID    | SLA ID |         Interface ID           |
      |   | ID  |           |        |                                |
      +---+-----+-----------+--------+--------------------------------+

      <--Public Topology--->   Site
                            <-------->
                             Topology
                                      <------Interface Identifier----->

   Where

      FP           Format Prefix (001)
      TLA ID       Top-Level Aggregation Identifier
      NLA ID       Next-Level Aggregation Identifier
      SLA ID       Site-Level Aggregation Identifier
      INTERFACE ID Interface Identifier


3.0 Rules for Assignment of Top-Level Aggregation ID's

   TLA ID's are assigned to organizations providing public transit
   topology.  They are specifically not assigned to organizations only
   providing leaf or private transit topology.  TLA ID assignment does
   not imply ownership.  It does imply stewardship over valuable
   Internet property.




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   The IAB and IESG have authorized the Internet Assigned Numbers
   Authority (IANA) as the appropriate entity to have the responsibility
   for the management of the IPv6 address space as defined in [ALLOC].

   The IANA will assign small blocks of TLA ID's to IPv6 registries.
   The registries will assign the TLA ID's to organizations meeting the
   requirements for TLA ID assignment.  When the registries have
   assigned all of their TLA ID's they can request that the IANA give
   them another block.  The blocks do not have to be contiguous.  The
   IANA may also assign TLA ID's to organizations directly.

   Registries are required to insure that organizations assigned TLA
   ID's meet the following requirements:

    - Must have a plan to offer public native IPv6 service within 6
      months from assignment.  The plan must include plan for NLA ID
      allocation.

    - Must have a plan or track record of providing public Internet
      transit service on fair, reasonable, and non-discriminatory terms,
      to other providers.  TLA ID's must not be assigned to
      organizations that are only providing leaf service even if
      multihomed.

    - Must provide registry services on fair, reasonable, and non-
      discriminatory terms, for the NLA ID address space it is
      responsible for under its TLA ID.  This must include both sites
      and next level providers.

    - Must provide transit routing and forwarding to all assigned TLA
      ID's on fair, reasonable, and non-discriminatory terms.
      Organizations are not allowed to filter out any specific TLA ID's
      (except temporarily for diagnostic purposes or emergency repair
      purposed).

    - Periodically (interval set by registry) provide to registry
      utilization statistics of the TLA ID it has custody of.  The
      organization must also show evidence of carrying TLA routing and
      transit traffic.  This can be in the form of traffic statistics,
      traceroutes, routing table dumps, or similar means.

   Organizations which are given custody of a TLA ID and fail to
   continue to meet these may have the TLA ID custody revoked.








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4.0 Rules Assignment of Next-Level Aggregation ID's

   Next-Level Aggregation ID's are used by organization assigned a TLA
   ID to create an addressing hierarchy and to identify sites.  The
   organization can assign the top part of the NLA ID in a manner to
   create an addressing hierarchy appropriate to its network.

   Organizations assigned TLA ID's are required to assume registry
   duties for the NLA ID's they assign.  Each organization assigned a
   NLA ID is required to assume registry duties for the next level NLA
   ID's it assigns.

   The design of the bit layout of the NLA ID space for a specific TLA
   ID is left to the organization responsible for that TLA ID.  Likewise
   the design of the bit layout of the next level NLA ID is the
   responsibility of the organization assigned the previous level NLA
   ID.  It is recommended that organizations assigning NLA address space
   use "slow start" allocation procedures as is currently done with IPv4
   CIDR blocks [CIDR].

   The design of an NLA ID allocation plan is a tradeoff between routing
   aggregation efficiency and flexibility.  Creating hierarchies allows
   for greater amount of aggregation and results in smaller routing
   tables.  Flat NLA ID assignment provides for easier allocation and
   attachment flexibility, but results in larger routing tables.


5.0 Acknowledgments

   The authors would like to express our thanks to Thomas Narten, Bob
   Fink, Matt Crawford, Allison Mankin, Jim Bound, Christian Huitema,
   Scott Bradner, Brian Carpenter, and John Stewart for their review and
   constructive comments.


5.0 References

   [AGGR]    Hinden, R., Deering, S., O'Dell, M., "An Aggregatable
             Global Unicast Address Format", Internet Draft, <draft-
             ietf-ipngwg-unicast-aggr-02.txt>, July 1997.

   [ALLOC]   IAB and IESG, "IPv6 Address Allocation Management",
             RFC1881, December 1995.

   [ARCH]    Hinden, R., "IP Version 6 Addressing Architecture",
             Internet Draft, <draft-ietf-ipngwg-addr-arch-v2-02.txt>,
             July 1997.




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   [AUTH]    Atkinson, R., "IP Authentication Header", RFC1826, August
             1995.

   [CIDR]    Fuller, V., T. Li, K. Varadhan, J. Yu, "Supernetting: an
             Address Assignment and Aggregation Strategy", RFC1338.

   [IPV6]    Deering, S., Hinden, R., Editors, "Internet Protocol,
             Version 6 (IPv6) Specification", RFC1883, December 1995.

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", RFC2119, BCP14, March 1997.


6.0 Security Considerations

   IPv6 addressing documents do not have any direct impact on Internet
   infrastructure security.  Authentication of IPv6 packets is defined
   in [AUTH].


7.0 Authors' Addresses

   Robert M. Hinden                     phone: 1 408 990-2004
   Ipsilon Networks, Inc.               email: hinden@ipsilon.com
   232 Java Drive
   Sunnyvale, CA 94089
   USA

   Mike O'Dell                          phone: 1 703 206-5890
   UUNET Technologies, Inc.             email: mo@uunet.uu.net
   3060 Williams Drive
   Fairfax, VA 22030
   USA


















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