Technical Summary
RFC 3107 specifies encodings and procedures for using BGP to
indicate that a particular router has bound either a single MPLS
label or a sequence of MPLS labels to a particular address prefix.
This is done by sending a BGP UPDATE message whose Network Layer
Reachability Information field contains both the prefix and the
MPLS label(s), and whose Next Hop field identifies the node at
which said prefix is bound to said label(s). Each such UPDATE also
advertises a path to the specified prefix, via the specified next
hop.
Although there are many implementations and deployments of
RFC3107, there are a number of issues with [RFC3107] that have
impeded interoperability in the past, and may potentially impede
interoperability in the future.
This document replaces and obsoletes RFC 3107. It defines a new
BGP Capability to be used when binding a sequence of labels to
a prefix; by using this Capability, the interoperability problems
alluded to above can be avoided.
This document also removes the unimplemented "Advertising Multiple
Routes to a Destination" feature, while specifying how to use
RFC 7911 to provide the same functionality.
This document also addresses the issue of the how UPDATEs that
bind labels to a given prefix interact with UPDATEs that advertise
paths to that prefix but do not bind labels to it. However, for
backwards compatibility, it declares most of these interactions
to be matters of local policy.
Working Group Summary
The MPLS working group does solidly support this docment, it
address well known interoperability problems. We had a good number
of people supporting working group adoption and later (in the
working last call) supporting publication.
The document has also been working group last called in IDR and
bess, the support from these groups are also strong.
There has been no controversies around this update of RFC 3107.
Document Quality
We know of several implementations of RFC 3107, thus a very good
understanding of the interoperability problems. We also know of
intents to implement the updated version. An implementation poll
has been started, and as soon as we have new information will
update this Shepherd Write-up.
Personnel
Who is the Document Shepherd for this document? Loa Andersson
Who is the Responsible Area Director? Deborah Brungard