Advertising IPv4 Network Layer Reachability Information with an IPv6 Next Hop
RFC 5549
Document | Type |
RFC - Proposed Standard
(May 2009; Errata)
Obsoleted by RFC 8950
|
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Authors | Eric Rosen , François Le Faucheur | ||
Last updated | 2018-02-06 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 5549 (Proposed Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Mark Townsley | ||
Send notices to | (None) |
Network Working Group F. Le Faucheur Request for Comments: 5549 E. Rosen Category: Standards Track Cisco Systems May 2009 Advertising IPv4 Network Layer Reachability Information with an IPv6 Next Hop 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. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract Multiprotocol BGP (MP-BGP) specifies that the set of network-layer protocols to which the address carried in the Next Hop field may belong is determined by the Address Family Identifier (AFI) and the Subsequent Address Family Identifier (SAFI). The current AFI/SAFI definitions for the IPv4 address family only have provisions for advertising a Next Hop address that belongs to the IPv4 protocol when advertising IPv4 Network Layer Reachability Information (NLRI) or VPN-IPv4 NLRI. This document specifies the extensions necessary to allow advertising IPv4 NLRI or VPN-IPv4 NLRI with a Next Hop address that belongs to the IPv6 protocol. This comprises an extension of the AFI/SAFI definitions to allow the address of the Next Hop for IPv4 NLRI or VPN-IPv4 NLRI to also belong to the IPv6 protocol, the encoding of the Next Hop in order to determine which of the protocols the address actually belongs to, and a new BGP Capability allowing MP-BGP Peers to dynamically discover whether they can exchange IPv4 NLRI and VPN-IPv4 NLRI with an IPv6 Next Hop. Le Faucheur & Rosen Standards Track [Page 1] RFC 5549 v4 NLRI with v6 NH May 2009 Table of Contents 1. Introduction ....................................................2 2. Requirements Language ...........................................4 3. Extension of AFI/SAFI Definitions for the IPv4 Address Family ...4 4. Use of BGP Capability Advertisement .............................5 5. Operations ......................................................7 6. Usage Examples ..................................................7 6.1. IPv4 over IPv6 Core ........................................7 6.2. IPv4 VPN over IPv6 Core ....................................8 7. IANA Considerations .............................................8 8. Security Considerations .........................................8 9. Acknowledgments .................................................9 10. References .....................................................9 10.1. Normative References ......................................9 10.2. Informative References ....................................9 1. Introduction Multiprotocol BGP (MP-BGP) [RFC4760] specifies that the set of network-layer protocols to which the address carried in the Next Hop field may belong is determined by the Address Family Identifier (AFI) and the Subsequent Address Family Identifier (SAFI). A number of existing AFI/SAFIs allow the Next Hop address to belong to a different address family than the Network Layer Reachability Information (NLRI). For example, the AFI/SAFI <25/65> used (as per [L2VPN-SIG]) in order to perform L2VPN auto-discovery, allows advertising NLRI that contains the identifier of a Virtual Private LAN Service (VPLS) instance or that identifies a particular pool of attachment circuits at a given Provider Edge (PE), while the Next Hop field contains the loopback address of a PE. Similarly, the AFI/SAFI <1/132> (defined in [RFC4684]) in order to advertise Route Target (RT) membership information, allows advertising NLRI that contains such RT membership information, while the Next Hop field contains the address of the advertising router. Furthermore, a number of these existing AFI/SAFIs allow the Next Hop to belong to either the IPv4 Network Layer Protocol or the IPv6 Network Layer Protocol, and specify the encoding of the Next Hop information in order to determine which of the protocols the address actually belongs to. For example, [RFC4684] allows the Next HopShow full document text