Technical Summary
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 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 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.
Working Group Summary
The WG supports the publication of this Document.
This Document was progressed rapidly in to address a simple gap in the current specifications
compared to all known deployed implementations.
This document was coordinated with the chairs of the IDR working group. It was progressed
in the BESS working group since most applications for it reside within the charter
of BESS.
Document Quality
The document was developed as a response to an observed gap in the current specifications
that did not reflect deployed implementations.
The ability to advertise an IPv6 next hop in an IPv4/VPN-IPv4 NLRI is something
that has been implemented and deployed and this document reflects the need to
standardise the procedures to ensure future interoperability. It also introduces
a new capability advertisement for this.
Personnel
The document shepherd is Matthew Bocci
The responsible Area Director is Martin Vigoureux