Technical Summary
This document describes extensions to the ISIS (ISIS) protocol to
support Multiprotocol Label Switching (MPLS) and Generalized MPLS
(GMPLS) Traffic Engineering (TE) for multiple Autonomous Systems
(ASes). It defines ISIS-TE extensions for the flooding of TE
information about inter-AS links which can be used to perform inter-
AS TE path computation.
No support for flooding information from within one AS to another AS
is proposed or defined in this document.
Working Group Summary
Good consensus reported. The document has had a good level of
discussions and review in CCAMP and in the ISIS working group.
In particular, it received considerable input from IS-IS experts
in its early stages. It was last called in both CCAMP and IS-IS
working groups and updated in response to comments.
Document Quality
There is a known implementation of the extensions, in addition to
a known implementation of the very similar OSPF document. There
was also good support for the work from other vendors with the
same objectives. Document review by the IS-IS working group
deserves special mention for its care and thoroughness.
Personnel
Adrian Farrel is the Document Shepherd for this document. Ross
Callon is the Responsible Area Director.
RFC Editor Note
Please add the following text to the end of the first paragraph
of section 5 (security considerations):
(e.g., using the cleartext passwords or Hashed Message
Authentication Codes - Message Digest 5 (HMAC-MD5) algorithm
which are defined in [ISIS] and [RFC3567bis] separately.)"
Please add the following paragraph to the end of section 5
(security considerations):
For a discussion of general security considerations for
IS-IS see [RFC3567bis].
Please add RFC3567bis to section 8.1 (normative references),
this refers to draft-ietf-isis-rfc3567bis (which should be an
RFC ahead of this draft -- it is now RFC 5304).
Please update Section 6.2 as follows:
OLD
This document defines the following new sub-TLV types, described in
Sections 3.3.1, 3.3.2 and 3.3.3, of top-level TLV 141 (see section
6.1 above) that need to be registered in the ISIS sub-TLV registry
for TLV 141, note that these three new sub-TLVs SHOULD NOT appear in
TLV 22 (or TLV 222) and MUST be ignored in TLV 22 (or TLV 222):
Type Description Length
---- ------------------------------ --------
23 Remote AS number 4
24 IPv4 Remote ASBR Identifier 4
25 IPv6 Remote ASBR Identifier 16
As described above in Section 3.1, the sub-TLVs which are defined in
[ISIS-TE], [ISIS-TE-V3] and other documents for describing the TE
properties of an TE link are applicable to describe an inter-AS TE
link and MAY be included in the Inter-AS Reachability TLV when
adverting inter-AS TE links. And it's possible that some sub-TLVs
may be defined for inclusion in both TLV 22 and TLV 141 in the
future. It's better if these sub-TLVs have the same registry value
no matter where they are included in TLV 22 or TLV 141. The same
condition will occur when these sub-TLVs need to be included in TLV
222. So, in order to simplify the registration and reduce the
potential code point conflict, this document suggests that TLV 22,
TLV 141 and TLV 222 share the same sub-TLV registry. The proposal is
that change the current Registry Name from "Sub-TLVs for TLV 22" to
"Sub-TLVs for TLV 22, 141 and 222" and add three columns ("May be
present on TLV 22","May be present on TLV 141" and "May be present
on TLV 222") to the registry for indicating whether a specific sub-
TLV may be present on the TLV.
NEW
This document defines the following new sub-TLV types, described in
Sections 3.3.1, 3.3.2 and 3.3.3, of top-level TLV 141 (see section
6.1 above) that need to be registered in the ISIS sub-TLV registry
for TLV 141, note that these three new sub-TLVs SHOULD NOT appear in
TLV 22 (or TLV 222) and MUST be ignored in TLV 22 (or TLV 222):
Type Description
---- ------------------------------
24 Remote AS number
25 IPv4 Remote ASBR Identifier
26 IPv6 Remote ASBR Identifier
As described above in Section 3.1, the sub-TLVs which are defined in
[ISIS-TE], [ISIS-TE-V3] and other documents for describing the TE
properties of an TE link are applicable to describe an inter-AS TE
link and MAY be included in the Inter-AS Reachability TLV when
adverting inter-AS TE links.
IANA is requested to update the registry currently specified as
"Sub-TLVs for TLV 22" to be named "Sub-TLVs for TLVs 22, 141, and
222". Three new columns should be added to the registry to show in
which TLVs the sub-TLVs may be present. All sub-TLVs currently
defined may be present in all three TLVs, hence the registry (with
the definition of the new sub-TLVs defined here) should read as
follows.
TLV TLV TLV
Type Description 22 141 222 Reference
------- ------------------------------------ --- --- --- ---------
0 Unassigned y y y
1 Unassigned y y y
2 Unassigned y y y
3 Administrative group (color) y y y [RFC5305]
4 Link Local/Remote Identifiers y y y
[RFC4205][RFC5307]
5 Unassigned y y y
6 IPv4 interface address y y y [RFC5305]
7 Unassigned y y y
8 IPv4 neighbor address y y y [RFC5305]
9 Maximum link bandwidth y y y [RFC5305]
10 Maximum reservable link bandwidth y y y [RFC5305]
11 Unreserved bandwidth y y y [RFC5305]
12 Unassigned y y y
13 Unassigned y y y
14 Unassigned y y y
15 Unassigned y y y
16 Unassigned y y y
17 Unassigned y y y
18 TE Default metric y y y [RFC5305]
19 Link-attributes y y y [RFC5029]
20 Link Protection Type y y y
[RFC4205][RFC5307]
21 Interface Switching Capability Desc y y y
[RFC4205][RFC5307]
22 Bandwidth Constraints y y y [RFC4124]
23 Unconstrained TE LSP Count (sub-)TLV y y y
[RFC-ietf-mpls-number-0-bw-te-lsps-12.txt]
24 Remote AS number n y n [This.I-D]
25 IPv4 Remote ASBR Identifier n y n [This.I-D]
26 IPv6 Remote ASBR Identifier n y n [This.I-D]
27-249 Unassigned
250-254 Reserved for Cisco-specific exts
255 Reserved for future expansion
Further sub-TLVs may be defined in the future for inclusion in any of
the TLVs 22, 141, or 222. The re-naming of the registry as above
ensures that there is no accidental overlap of sub-TLV codepoints.
The introduction of the columns within the registry clarify the use
of the sub-TLVs.
IANA Note
Please note substantial IANA update in the RFC editor's note.