Technical Summary
This document extends ICMP error mesages (both IPv4 and
IPv6) with a mechanism that allows sending additional
data. A number of use cases for such additional
data have been proposed, but this draft covers
only the generic format in which such data can
be carried.
Working Group Summary
This document has been discussed originally in the
MPLS WG, at which time it became apparent that
there is a generic part and an MPLS specific
usage. In 2005-2006 this document has been discussed
in the Internet Area meetings and list.
There were a number of controversial discussion
items in the Internet Area discussion, including,
for instance, whether IPv6 support should be
included and the detailed design of the extension
and length field formats. The final result
represents the rough consensus of the group.
Protocol Quality
This specification has been reviewed by Jari Arkko
for the IESG. In addition, a number of reviewers
performed detailed reviews during list discussion.
These reviewers included Pekka Savola, Pekka Nikander,
Fernando Gont, Joe Touch and others.
In late summer 2006 the IESG discussed what criteria
we should have for changing something as central
as the ICMP. As a result of these discussions
the authors enlisted a university group to perform
experimental analysis of a number of common
devices and how they interact with the proposed
extensions. No deviation or error in the normal
ICMP processing was observed during these tests.
An early version of this specification (without
the length field) has also been deployed in the
MPLS space for both IPv4 and IPv6, by multiple
vendors. It has been used through the years
for debugging MPLS networks.