Technical Summary
This document describes extensions to the Intermediate System to
Intermediate System (IS-IS) protocol to support optimal routing
within a two-level domain. The IS-IS protocol is specified in ISO
10589, with extensions for supporting IPv4 (Internet Protocol)
specified in RFC 1195. This document replaces RFC 2966. This
document extends the semantics presented in RFC 1195 so that a
routing domain running with both level 1 and level 2 Intermediate
Systems (IS) [routers] can distribute IP prefixes between level 1
and level 2 and vice versa.
Working Group Summary
This is part of a series of seven IS-IS RFCs that were originally
published as informational for historic reasons, but that are now
being updated to proposed standard. There is broad consensus in the
WG for this change.
Document Quality
This document has been widely reviewed, and is implemented and
deployed.
Personnel
Chris Hopps and Dave Ward have jointly worked as document shepherds
for this bunch of seven documents. Ross Callon is the responsible AD.
RFC Editor Note
Please replace section 6 (Security Considerations) as follows:
OLD
6. Security Considerations
This document raises no new security issues for IS-IS.
NEW
6. Security Considerations
This document raises no new security issues for IS-IS; for
general security considerations for IS-IS see [RFC3567bis].
Please add the following informative reference in section 8.2:
[RFC3567bis] Li, T. and R. Atkinson, "Intermediate System to
Intermediate System (IS-IS) Cryptographic Authentication",
work in progress.
Also please note that this last reference is within a few days
of being approved, and it probably would be preferable to hold
this document until you can publish both at the same time.
Please update all references to [RFC3784] with references to
[draft-ietf-isis-te-bis]. If I counted right, this includes five
references in the regular text, plus the entry for 3784 in the
informative references section. Please note that
draft-ietf-isis-te-bis is within a few days of being approved,
and it probably would be preferable to hold this document until
you can publish both (and actually all seven IS-IS documents
being progressed) at the same time.
In section 2, third paragraph, second sentence:
OLD
However, to prevent routing-loops, L1L2 routers must not
advertise L2->L1 inter-area routes that they learn via L1
routing, back into L2.
NEW
However, to prevent routing-loops, L1L2 routers MUST NOT
advertise L2->L1 inter-area routes that they learn via L1
routing, back into L2.
In section 4, third paragraph, first sentence:
OLD
Implementations that follow RFC 1195 should ignore bit 8 in the
default metric field when computing routes.
NEW
Implementations that follow RFC 1195 SHOULD ignore bit 8 in the
default metric field when computing routes.