RFC 8950

Advertising IPv4 Network Layer Reachability Information (NLRI) with an IPv6 Next Hop, November 2020

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RFC 5549
S. Litkowski
S. Agrawal
K. Ananthamurthy
K. Patel
bess (rtg)

Cite this RFC: TXT  |  XML

DOI:  10.17487/RFC8950

Discuss this RFC: Send questions or comments to bess@ietf.org

Other actions: Submit Errata  |  Find IPR Disclosures from the IETF


Multiprotocol BGP (MP-BGP) specifies that the set of usable next-hop address families is determined by the Address Family Identifier (AFI) and the Subsequent Address Family Identifier (SAFI). The 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 the advertising of 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 to determine which of the protocols the address actually belongs to, and a BGP Capability allowing MP-BGP peers to dynamically discover whether they can exchange IPv4 NLRI and VPN-IPv4 NLRI with an IPv6 next hop. This document obsoletes RFC 5549.

For the definition of Status, see RFC 2026.

For the definition of Stream, see RFC 8729.

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