OSPF for IPv6
RFC 5340
Document | Type |
RFC - Proposed Standard
(July 2008; Errata)
Obsoletes RFC 2740
|
|
---|---|---|---|
Authors | Dennis Ferguson , Acee Lindem , John Moy | ||
Last updated | 2020-01-21 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized with errata bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5340 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | David Ward | ||
Send notices to | (None) |
Network Working Group R. Coltun Request for Comments: 5340 Acoustra Productions Obsoletes: 2740 D. Ferguson Category: Standards Track Juniper Networks J. Moy Sycamore Networks, Inc A. Lindem, Ed. Redback Networks July 2008 OSPF for IPv6 Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Abstract This document describes the modifications to OSPF to support version 6 of the Internet Protocol (IPv6). The fundamental mechanisms of OSPF (flooding, Designated Router (DR) election, area support, Short Path First (SPF) calculations, etc.) remain unchanged. However, some changes have been necessary, either due to changes in protocol semantics between IPv4 and IPv6, or simply to handle the increased address size of IPv6. These modifications will necessitate incrementing the protocol version from version 2 to version 3. OSPF for IPv6 is also referred to as OSPF version 3 (OSPFv3). Changes between OSPF for IPv4, OSPF Version 2, and OSPF for IPv6 as described herein include the following. Addressing semantics have been removed from OSPF packets and the basic Link State Advertisements (LSAs). New LSAs have been created to carry IPv6 addresses and prefixes. OSPF now runs on a per-link basis rather than on a per-IP-subnet basis. Flooding scope for LSAs has been generalized. Authentication has been removed from the OSPF protocol and instead relies on IPv6's Authentication Header and Encapsulating Security Payload (ESP). Even with larger IPv6 addresses, most packets in OSPF for IPv6 are almost as compact as those in OSPF for IPv4. Most fields and packet- size limitations present in OSPF for IPv4 have been relaxed. In addition, option handling has been made more flexible. Coltun, et al. Standards Track [Page 1] RFC 5340 OSPF for IPv6 July 2008 All of OSPF for IPv4's optional capabilities, including demand circuit support and Not-So-Stubby Areas (NSSAs), are also supported in OSPF for IPv6. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Requirements Notation . . . . . . . . . . . . . . . . . . 4 1.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 4 2. Differences from OSPF for IPv4 . . . . . . . . . . . . . . . . 5 2.1. Protocol Processing Per-Link, Not Per-Subnet . . . . . . . 5 2.2. Removal of Addressing Semantics . . . . . . . . . . . . . 5 2.3. Addition of Flooding Scope . . . . . . . . . . . . . . . . 6 2.4. Explicit Support for Multiple Instances per Link . . . . . 6 2.5. Use of Link-Local Addresses . . . . . . . . . . . . . . . 7 2.6. Authentication Changes . . . . . . . . . . . . . . . . . . 7 2.7. Packet Format Changes . . . . . . . . . . . . . . . . . . 8 2.8. LSA Format Changes . . . . . . . . . . . . . . . . . . . . 9 2.9. Handling Unknown LSA Types . . . . . . . . . . . . . . . . 10 2.10. Stub/NSSA Area Support . . . . . . . . . . . . . . . . . . 11 2.11. Identifying Neighbors by Router ID . . . . . . . . . . . . 11 3. Differences with RFC 2740 . . . . . . . . . . . . . . . . . . 11 3.1. Support for Multiple Interfaces on the Same Link . . . . . 11 3.2. Deprecation of MOSPF for IPv6 . . . . . . . . . . . . . . 12 3.3. NSSA Specification . . . . . . . . . . . . . . . . . . . . 12 3.4. Stub Area Unknown LSA Flooding Restriction Deprecated . . 12 3.5. Link LSA Suppression . . . . . . . . . . . . . . . . . . . 12 3.6. LSA Options and Prefix Options Updates . . . . . . . . . . 13 3.7. IPv6 Site-Local Addresses . . . . . . . . . . . . . . . . 13 4. Implementation Details . . . . . . . . . . . . . . . . . . . . 13 4.1. Protocol Data Structures . . . . . . . . . . . . . . . . . 14 4.1.1. The Area Data Structure . . . . . . . . . . . . . . . 15 4.1.2. The Interface Data Structure . . . . . . . . . . . . . 15 4.1.3. The Neighbor Data Structure . . . . . . . . . . . . . 16 4.2. Protocol Packet Processing . . . . . . . . . . . . . . . . 17Show full document text