draft-ietf-ccamp-isis-interas-te-extension-00.txt   draft-ietf-ccamp-isis-interas-te-extension-01.txt 
Network work group Mach Chen Network working group M. Chen
Internet Draft Renhai Zhang Internet Draft Renhai Zhang
Expires: August 2008 Huawei Technologies Co.,Ltd Expires: October 2008 Huawei Technologies Co.,Ltd
Category: Standards Track Xiaodong Duan Category: Standards Track Xiaodong Duan
China Mobile China Mobile
February 3, 2008 April 10, 2008
ISIS Extensions in Support of Inter-AS Multiprotocol Label Switching ISIS Extensions in Support of Inter-AS Multiprotocol Label Switching
(MPLS) and Generalized MPLS (GMPLS) Traffic Engineering (MPLS) and Generalized MPLS (GMPLS) Traffic Engineering
draft-ietf-ccamp-isis-interas-te-extension-00.txt draft-ietf-ccamp-isis-interas-te-extension-01.txt
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Abstract Abstract
This document describes extensions to the ISIS (ISIS) protocol to This document describes extensions to the ISIS (ISIS) protocol to
support Multiprotocol Label Switching (MPLS) and Generalized MPLS support Multiprotocol Label Switching (MPLS) and Generalized MPLS
(GMPLS) Traffic Engineering (TE) for multiple Autonomous Systems (GMPLS) Traffic Engineering (TE) for multiple Autonomous Systems
(ASes). It defines ISIS-TE extensions for the flooding of TE (ASes). It defines ISIS-TE extensions for the flooding of TE
information about inter-AS links which can be used to perform inter- information about inter-AS links which can be used to perform inter-
AS TE path computation. AS TE path computation.
No support for flooding TE information from other outside the AS is No support for flooding TE information from outside the AS is
proposed or defined in this document. proposed or defined in this document.
Conventions used in this document Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC-2119 [RFC2119]. document are to be interpreted as described in RFC-2119 [RFC2119].
Table of Contents Table of Contents
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2.2. Per-Domain Path Determination...........................4 2.2. Per-Domain Path Determination...........................4
2.3. Backward Recursive Path Computation.....................6 2.3. Backward Recursive Path Computation.....................6
3. Extensions to ISIS-TE........................................7 3. Extensions to ISIS-TE........................................7
3.1. Inter-AS Reachability TLV...............................8 3.1. Inter-AS Reachability TLV...............................8
3.2. TE Router ID............................................9 3.2. TE Router ID............................................9
3.3. Sub-TLV Detail.........................................10 3.3. Sub-TLV Detail.........................................10
3.3.1. Remote AS Number Sub-TLV..........................10 3.3.1. Remote AS Number Sub-TLV..........................10
3.3.2. IPv4 Remote ASBR ID Sub-TLV.......................10 3.3.2. IPv4 Remote ASBR ID Sub-TLV.......................10
3.3.3. IPv6 Remote ASBR ID Sub-TLV.......................11 3.3.3. IPv6 Remote ASBR ID Sub-TLV.......................11
3.3.4. IPv4 TE Router ID sub-TLV.........................12 3.3.4. IPv4 TE Router ID sub-TLV.........................12
3.3.5. IPv6 TE Router ID sub-TLV.........................12 3.3.5. IPv6 TE Router ID sub-TLV.........................13
4. Procedure for Inter-AS TE Links.............................13 4. Procedure for Inter-AS TE Links.............................13
4.1. Origin of Proxied TE Information.......................14 4.1. Origin of Proxied TE Information.......................14
5. Security Considerations.....................................14 5. Security Considerations.....................................15
6. IANA Considerations.........................................15 6. IANA Considerations.........................................15
6.1. Inter-AS Reachability TLV..............................15 6.1. Inter-AS Reachability TLV..............................15
6.2. Sub-TLVs for the Inter-AS Reachability TLV.............15 6.2. Sub-TLVs for the Inter-AS Reachability TLV.............16
6.3. Sub-TLVs for the IS-IS Router Capability TLV...........16 6.3. Sub-TLVs for the IS-IS Router Capability TLV...........16
7. Acknowledgments.............................................16 7. Acknowledgments.............................................16
8. References..................................................16 8. References..................................................17
8.1. Normative References...................................16 8.1. Normative References...................................17
8.2. Informative References.................................17 8.2. Informative References.................................17
Authors' Addresses.............................................18 Authors' Addresses.............................................18
Intellectual Property Statement................................18 Intellectual Property Statement................................18
Disclaimer of Validity.........................................19 Disclaimer of Validity.........................................19
Copyright Statement............................................19 Copyright Statement............................................19
1. Introduction 1. Introduction
[ISIS-TE] defines extensions to the ISIS protocol [ISIS] to support [ISIS-TE] defines extensions to the ISIS protocol [ISIS] to support
intra-area Traffic Engineering (TE). The extensions provide a way of intra-area Traffic Engineering (TE). The extensions provide a way of
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o There is no mechanism proposed to distribute any form of TE o There is no mechanism proposed to distribute any form of TE
reachability information for destinations outside the AS. reachability information for destinations outside the AS.
o There is no proposed change to the PCE architecture or usage. o There is no proposed change to the PCE architecture or usage.
o TE aggregation is not supported or recommended. o TE aggregation is not supported or recommended.
o There is no exchange of private information between ASes. o There is no exchange of private information between ASes.
o No ISIS adjacencies are formed on the inter-AS link. o No OSPF adjacencies are formed on the inter-AS link.
Note also that the extensions proposed in this document are used only
to advertise information about inter-AS TE links. As such these
extensions address an entirely different problem from L1VPN Auto-
Discovery [L1VPN-OSPF-AD] which defines how TE information about
links between Customer Edge (CE) equipment and Provider Edge (PE)
equipment can be advertised in OSPF-TE alongside the auto-discovery
information for the CE-PE links. There is no overlap between this
document and [L1VPN-OSPF-AD].
2.2. Per-Domain Path Determination 2.2. Per-Domain Path Determination
In the per-domain method of determining an inter-AS path for an MPLS- In the per-domain method of determining an inter-AS path for an MPLS-
TE LSP, when an LSR that is an entry-point to an AS receives a PATH TE LSP, when an LSR that is an entry-point to an AS receives a Path
message from an upstream AS with an ERO containing a next hop that is message from an upstream AS with an ERO containing a next hop that is
an AS number, it needs to find which LSRs (ASBRs) within the local AS an AS number, it needs to find which LSRs (ASBRs) within the local AS
are connected to the downstream AS so that it can compute a TE LSP are connected to the downstream AS so that it can compute a TE LSP
segment across the AS to one of those LSRs and forward the PATH segment across the local AS to one of those LSRs and forward the PATH
message to it and hence into the next AS. See Figure 1 for an message to it and hence into the next AS. See Figure 1 for an example:
example :
R1------R3----R5-----R7------R9-----R11 R1------R3----R5-----R7------R9-----R11
| | \ | / | | | \ | / |
| | \ | ---- | | | \ | ---- |
| | \ | / | | | \ | / |
R2------R4----R6 --R8------R10----R12 R2------R4----R6 --R8------R10----R12
: : : :
<-- AS1 -->:<---- AS2 --->:<--- AS3 ---> <-- AS1 -->:<---- AS2 --->:<--- AS3 --->
Figure 1: Inter-AS Reference Model Figure 1: Inter-AS Reference Model
The figure shows three ASes (AS1, AS2, and AS3) and twelve LSRs (R1 The figure shows three ASes (AS1, AS2, and AS3) and twelve LSRs (R1
through R12). R3 and R4 are ASBRs in AS1. R5, R6, R7, and R8 are through R12). R3 and R4 are ASBRs in AS1. R5, R6, R7, and R8 are
ASBRs in AS2. R9 and R10 are ASBRs in AS3. ASBRs in AS2. R9 and R10 are ASBRs in AS3.
If it is planned to establish an inter-AS TE LSP from R1 to R12, the If an inter-AS TE LSP is planned to be established from R1 to R12,
AS sequence will be: AS1, AS2, AS3. the AS sequence will be: AS1, AS2, AS3.
Suppose that the Path message enters AS2 from R3. The next hop in the Suppose that the Path message enters AS2 from R3. The next hop in the
ERO shows AS3, and R5 must determine a path segment across AS2 to ERO shows AS3, and R5 must determine a path segment across AS2 to
reach AS3. It has a choice of three exit points from AS2 (R6, R7, and reach AS3. It has a choice of three exit points from AS2 (R6, R7, and
R8) and it needs to know which of these provide TE connectivity to R8) and it needs to know which of these provide TE connectivity to
AS3, and whether the TE connectivity (for example, available AS3, and whether the TE connectivity (for example, available
bandwidth) is adequate for the requested LSP. bandwidth) is adequate for the requested LSP.
Alternatively, if the next hop in the ERO is the entry ASBR for AS3 Alternatively, if the next hop in the ERO is the entry ASBR for AS3
(say R9), R5 needs to know which of its exit ASBRs has a TE link that (say R9), R5 needs to know which of its exit ASBRs has a TE link that
connects to R9. Since there may be multiple ASBRs that are connected connects to R9. Since there may be multiple ASBRs that are connected
to R9 (both R7 and R8 in this example), R5 also needs to know the TE to R9 (both R7 and R8 in this example), R5 also needs to know the TE
properties of the inter-AS TE links so that it can select the correct properties of the inter-AS TE links so that it can select the correct
exit ASBR. exit ASBR.
Once the path message reaches the exit ASBR, any choice of inter-AS Once the path message reaches the exit ASBR, any choice of inter-AS
TE link can be made by the ASBR if not already made by entry ASBR TE link can be made by the ASBR if not already made by entry ASBR
that computed the segment. that computed the segment.
More details can be found in the Section 4.0 of [PD-PATH], which More details can be found in the Section 4. of [PD-PATH], which
clearly points out why advertising of inter-AS links is desired. clearly points out why advertising of inter-AS links is desired.
To enable R5 to make the correct choice of exit ASBR the following To enable R5 to make the correct choice of exit ASBR the following
information is needed: information is needed:
o List of all inter-AS TE links for the local AS. o List of all inter-AS TE links for the local AS.
o TE properties of each inter-AS TE link. o TE properties of each inter-AS TE link.
o AS number of the neighboring AS connected to by each inter-AS TE o AS number of the neighboring AS connected to by each inter-AS TE
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| | \ | / | | | \ | / |
| | \ | ---- | | | \ | ---- |
| | \ | / | | | \ | / |
R2------R4----R6 --R8------R10----R12 R2------R4----R6 --R8------R10----R12
: : : :
<-- AS1 -->:<---- AS2 --->:<--- AS3 ---> <-- AS1 -->:<---- AS2 --->:<--- AS3 --->
Figure 2: BRPC for Inter-AS Reference Model Figure 2: BRPC for Inter-AS Reference Model
The figure shows three ASes (AS1, AS2, and AS3), three PCEs(PCE1, The figure shows three ASes (AS1, AS2, and AS3), three PCEs(PCE1,
PCE2, and PCE3) and twelve LSRs (R1 through R12). R3 and R4 are ASBRs PCE2, and PCE3), and twelve LSRs (R1 through R12). R3 and R4 are
in AS1. R5, R6, R7, and R8 are ASBRs in AS2. R9 and R10 are ASBRs in ASBRs in AS1. R5, R6, R7, and R8 are ASBRs in AS2. R9 and R10 are
AS3. PCE1, PCE2, and PCE3 cooperate to perform inter-AS path ASBRs in AS3. PCE1, PCE2, and PCE3 cooperate to perform inter-AS path
computation and are responsible for path segment computation within computation and are responsible for path segment computation within
their own domains. their own domain(s).
If it is planned to establish an inter-AS TE LSP from R1 to R12, the If an inter-AS TE LSP is planned to be established from R1 to R12,
traversed domains are assumed to be selected: AS1->AS2->AS3, and the the traversed domains are assumed to be selected: AS1->AS2->AS3, and
PCE chain is: PCE1->PCE2->PCE3. First, the path computation request the PCE chain is: PCE1->PCE2->PCE3. First, the path computation
originated from the PCC (R1) is relayed by PCE1 and PCE2 along the request originated from the PCC (R1) is relayed by PCE1 and PCE2
PCE chain to PCE3, then PCE3 begins to compute the path segments from along the PCE chain to PCE3, then PCE3 begins to compute the path
the entry boundary nodes that provide connection from AS2 to the segments from the entry boundary nodes that provide connection from
destination (R12). But, to provide suitable path segments, PCE3 must AS2 to the destination (R12). But, to provide suitable path segments,
determine which entry boundary nodes provide connectivity to its PCE3 must determine which entry boundary nodes provide connectivity
upstream neighbor AS (identified by its AS number), and must know the to its upstream neighbor AS (identified by its AS number), and must
TE properties of the inter-AS TE links. In the same way, PCE2 also know the TE properties of the inter-AS TE links. In the same way,
needs to determine the entry boundary nodes according to its upstream PCE2 also needs to determine the entry boundary nodes according to
neighbor AS and the inter-AS TE link capabilities. its upstream neighbor AS and the inter-AS TE link capabilities.
Thus, to support Backward Recursive Path Computation the same Thus, to support Backward Recursive Path Computation the same
information listed in Section 2.2 is required. information listed in Section 2.2 is required. The AS number of the
neighboring AS connected to by each inter-AS TE link is particularly
important.
3. Extensions to ISIS-TE 3. Extensions to ISIS-TE
Note that this document does not define mechanisms for distribution Note that this document does not define mechanisms for distribution
of TE information from one AS to another, does not distribute any of TE information from one AS to another, does not distribute any
form of TE reachability information for destinations outside the AS, form of TE reachability information for destinations outside the AS,
does not change the PCE architecture or usage, does not suggest or does not change the PCE architecture or usage, does not suggest or
recommend any form of TE aggregation, and does not feed private recommend any form of TE aggregation, and does not feed private
information between ASes. See Section 2.1. information between ASes. See Section 2.1.
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inclusion in the Extended IS Reachability TLV are applicable to be inclusion in the Extended IS Reachability TLV are applicable to be
included in the Inter-AS Reachability TLV for inter-AS TE links included in the Inter-AS Reachability TLV for inter-AS TE links
advertisement. And another two new sub-TLVs are defined for inclusion advertisement. And another two new sub-TLVs are defined for inclusion
in the IS-IS Router Capability TLV to carry the TE Router ID when the in the IS-IS Router Capability TLV to carry the TE Router ID when the
TE Router ID is needed to reach all routers within an entire ISIS TE Router ID is needed to reach all routers within an entire ISIS
routing domain. routing domain.
3.1. Inter-AS Reachability TLV 3.1. Inter-AS Reachability TLV
The Inter-AS Reachability TLV has type 141 (which needs to be The Inter-AS Reachability TLV has type 141 (which needs to be
confirmed by IANA), it contains a data structure consisting of: confirmed by IANA see Section 6.1), it contains a data structure
consisting of:
7 octets of System ID and Pseudonode Number 7 octets of System ID and Pseudonode Number
3 octets of default metric 3 octets of default metric
1 octet of control information, consisting of: 1 octet of control information, consisting of:
1 bit of flooding-scope information 1 bit of flooding-scope information
1 bit of up/down information 1 bit of up/down information
6 bits reserved 6 bits reserved
1 octet of length of sub-TLVs 1 octet of length of sub-TLVs
0-243 octets of sub-TLVs 0-243 octets of sub-TLVs
where each sub-TLV consists of a sequence of: where each sub-TLV consists of a sequence of:
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information" field which is consisted of a flooding-scope bit, a information" field which is consisted of a flooding-scope bit, a
up/down bit and 6 reserved bits. up/down bit and 6 reserved bits.
As the S bit defined in [ISIS-CAP], the flooding-scope bit is used to As the S bit defined in [ISIS-CAP], the flooding-scope bit is used to
control the flooding scope of the Inter-AS Reachability TLV. When the control the flooding scope of the Inter-AS Reachability TLV. When the
flooding-scope bit is set to 1, the Inter-AS Reachability TLV MUST be flooding-scope bit is set to 1, the Inter-AS Reachability TLV MUST be
flooded into the entire ISIS routing domain. If the flooding-scope flooded into the entire ISIS routing domain. If the flooding-scope
bit is set to 0, the Inter-AS Reachability TLV MUST NOT be leaked bit is set to 0, the Inter-AS Reachability TLV MUST NOT be leaked
between different levels. And this flooding-scope bit MUST NOT be between different levels. And this flooding-scope bit MUST NOT be
modified during the TLV leaking. The choice between the use of 0 or 1 modified during the TLV leaking. The choice between the use of 0 or 1
is a network-wide policy choice, and configuration control SHOULD be is a AS-wide policy choice, and configuration control SHOULD be
provided in ASBR implementations that supports the advertisement of provided in ASBR implementations that supports the advertisement of
inter-AS TE links. inter-AS TE links.
The semantics of the up/down bit in the Inter-AS Reachability TLV are The semantics of the up/down bit in the Inter-AS Reachability TLV are
identical to the semantics of the up/down bit defined in [ISIS-TE]. identical to the semantics of the up/down bit defined in [ISIS-TE].
It can be used to facilitate the redistribution of inter-AS TE It can be used to facilitate the redistribution of inter-AS TE
information freely between level 1 and level 2. And the up/down bit information freely between level 1 and level 2. And the up/down bit
MUST be set to 0 when the Inter-AS TE information first injected into MUST be set to 0 when the Inter-AS TE information first injected into
ISIS [ISIS], and the up/dawn bit MUST be set to 1 if the Inter-AS TE ISIS [ISIS], and the up/dawn bit MUST be set to 1 if the Inter-AS TE
information needs to be advertised from high level to low level. information needs to be advertised from high level to low level.
The sub-TLVs which are defined in [ISIS-TE], [ISIS-TE-V3] and other 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 also documents for describing the TE properties of an TE link are also
applicable to be carried in the Inter-AS Reachability TLV to describe applicable to be carried in the Inter-AS Reachability TLV to describe
the TE properties of an Inter-AS TE link. Apart from these sub-TLVs, the TE properties of an Inter-AS TE link. Apart from these sub-TLVs,
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information freely between level 1 and level 2. And the up/down bit information freely between level 1 and level 2. And the up/down bit
MUST be set to 0 when the Inter-AS TE information first injected into MUST be set to 0 when the Inter-AS TE information first injected into
ISIS [ISIS], and the up/dawn bit MUST be set to 1 if the Inter-AS TE ISIS [ISIS], and the up/dawn bit MUST be set to 1 if the Inter-AS TE
information needs to be advertised from high level to low level. information needs to be advertised from high level to low level.
The sub-TLVs which are defined in [ISIS-TE], [ISIS-TE-V3] and other 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 also documents for describing the TE properties of an TE link are also
applicable to be carried in the Inter-AS Reachability TLV to describe applicable to be carried in the Inter-AS Reachability TLV to describe
the TE properties of an Inter-AS TE link. Apart from these sub-TLVs, the TE properties of an Inter-AS TE link. Apart from these sub-TLVs,
three new sub-TLVs are defined for inclusion in the Inter-AS three new sub-TLVs are defined for inclusion in the Inter-AS
Reachability TLV in the document: Reachability TLV in this document:
Sub-TLV type Length Name Sub-TLV type Length Name
------------ ------ --------------------------- ------------ ------ ---------------------------
23 4 Remote AS number 23 4 Remote AS number
24 4 IPv4 Remote ASBR Identifier 24 4 IPv4 Remote ASBR Identifier
25 16 IPv6 Remote ASBR Identifier 25 16 IPv6 Remote ASBR Identifier
The detailed definitions of the three new sub-TLVs are described in The detailed definitions of the three new sub-TLVs are described in
Section 3.3. Section 3.3.
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3.3. Sub-TLV Detail 3.3. Sub-TLV Detail
3.3.1. Remote AS Number Sub-TLV 3.3.1. Remote AS Number Sub-TLV
A new sub-TLV, the Remote AS Number sub-TLV is defined for inclusion A new sub-TLV, the Remote AS Number sub-TLV is defined for inclusion
in the Inter-AS Reachability TLV when advertising inter-AS links. The in the Inter-AS Reachability TLV when advertising inter-AS links. The
Remote AS Number sub-TLV specifies the AS number of the neighboring Remote AS Number sub-TLV specifies the AS number of the neighboring
AS to which the advertised link connects. AS to which the advertised link connects.
The Remote AS number sub-TLV is TLV type 23 (which needs to be The Remote AS number sub-TLV is TLV type 23 (which needs to be
confirmed by IANA), and is four octets in length. The format is as confirmed by IANA see Section 6.2), and is four octets in length. The
follows: format is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote AS Number | | Remote AS Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Remote AS number field has 4 octets. When only two octets are The Remote AS number field has 4 octets. When only two octets are
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order) two octets MUST be set to zero. The Remote AS Number Sub-TLV order) two octets MUST be set to zero. The Remote AS Number Sub-TLV
MUST be included when a router advertises an inter-AS TE link. MUST be included when a router advertises an inter-AS TE link.
3.3.2. IPv4 Remote ASBR ID Sub-TLV 3.3.2. IPv4 Remote ASBR ID Sub-TLV
A new sub-TLV, which is referred to as the IPv4 Remote ASBR ID sub- A new sub-TLV, which is referred to as the IPv4 Remote ASBR ID sub-
TLV, is defined for inclusion in the Inter-AS Reachability TLV when TLV, is defined for inclusion in the Inter-AS Reachability TLV when
advertising inter-AS links. The IPv4 Remote ASBR ID sub-TLV specifies advertising inter-AS links. The IPv4 Remote ASBR ID sub-TLV specifies
the IPv4 identifier of the remote ASBR to which the advertised inter- the IPv4 identifier of the remote ASBR to which the advertised inter-
AS link connects. This could be any stable and routable IPv4 address AS link connects. This could be any stable and routable IPv4 address
of the remote ASBR. Use of the TE Router ID is RECOMMENDED. of the remote ASBR. Use of the TE Router ID as specified in the
Traffic Engineering Router ID TLV [ISIS-TE] is RECOMMENDED.
The IPv4 Remote ASBR ID sub-TLV is TLV type 24 (which needs to be The IPv4 Remote ASBR ID sub-TLV is TLV type 24 (which needs to be
confirmed by IANA), and is four octets in length. The format of the confirmed by IANA see Section 6.2), and is four octets in length. The
IPv4 Remote ASBR ID sub-TLV is as follows: format of the IPv4 Remote ASBR ID sub-TLV is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote ASBR ID | | Remote ASBR ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The IPv4 Remote ASBR ID sub-TLV MUST be included if the neighboring The IPv4 Remote ASBR ID sub-TLV MUST be included if the neighboring
skipping to change at page 11, line 27 skipping to change at page 11, line 31
IPv6 Remote ASBR ID sub-TLV MAY both be present in an Extended IS IPv6 Remote ASBR ID sub-TLV MAY both be present in an Extended IS
Reachability TLV. Reachability TLV.
3.3.3. IPv6 Remote ASBR ID Sub-TLV 3.3.3. IPv6 Remote ASBR ID Sub-TLV
A new sub-TLV, which is referred to as the IPv6 Remote ASBR ID sub- A new sub-TLV, which is referred to as the IPv6 Remote ASBR ID sub-
TLV, is defined for inclusion in the Inter-AS Reachability TLV when TLV, is defined for inclusion in the Inter-AS Reachability TLV when
advertising inter-AS links. The IPv6 Remote ASBR ID sub-TLV specifies advertising inter-AS links. The IPv6 Remote ASBR ID sub-TLV specifies
the IPv6 identifier of the remote ASBR to which the advertised inter- the IPv6 identifier of the remote ASBR to which the advertised inter-
AS link connects. This could be any stable and routable IPv6 address AS link connects. This could be any stable and routable IPv6 address
of the remote ASBR. Use of the TE Router ID is RECOMMENDED. of the remote ASBR. Use of the TE Router ID as specified in the IPv6
Traffic Engineering Router ID TLV [ISIS-TE-V3] is RECOMMENDED.
The IPv6 Remote ASBR ID sub-TLV is TLV type 25 (which needs to be The IPv6 Remote ASBR ID sub-TLV is TLV type 25 (which needs to be
confirmed by IANA), and is sixteen octets in length. The format of confirmed by IANA see Section 6.2), and is sixteen octets in length.
the IPv6 Remote ASBR ID sub-TLV is as follows: The format of the IPv6 Remote ASBR ID sub-TLV is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote ASBR ID | | Remote ASBR ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote ASBR ID (continued) | | Remote ASBR ID (continued) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 12, line 8 skipping to change at page 12, line 28
The IPv6 Remote ASBR ID sub-TLV MUST be included if the neighboring The IPv6 Remote ASBR ID sub-TLV MUST be included if the neighboring
ASBR has an IPv6 address. If the neighboring ASBR does not have an ASBR has an IPv6 address. If the neighboring ASBR does not have an
IPv6 address, the IPv4 Remote ASBR ID sub-TLV MUST be included IPv6 address, the IPv4 Remote ASBR ID sub-TLV MUST be included
instead. An IPv4 Remote ASBR ID sub-TLV and IPv6 Remote ASBR ID sub- instead. An IPv4 Remote ASBR ID sub-TLV and IPv6 Remote ASBR ID sub-
TLV MAY both be present in an Extended IS Reachability TLV. TLV MAY both be present in an Extended IS Reachability TLV.
3.3.4. IPv4 TE Router ID sub-TLV 3.3.4. IPv4 TE Router ID sub-TLV
The IPv4 TE Router ID sub-TLV is TLV type 11 (which needs to be The IPv4 TE Router ID sub-TLV is TLV type 11 (which needs to be
confirmed by IANA), and is four octets in length. The format of the confirmed by IANA see Section 6.3), and is four octets in length. The
IPv4 TE Router ID sub-TLV is as follows: format of the IPv4 TE Router ID sub-TLV is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TE Router ID | | TE Router ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
When the TE Router ID is needed to reach all routers within an entire When the TE Router ID is needed to reach all routers within an entire
skipping to change at page 12, line 31 skipping to change at page 13, line 8
in its LSP. And if an ASBR supports Traffic Engineering for IPv4, the in its LSP. And if an ASBR supports Traffic Engineering for IPv4, the
IPv4 TE Router ID sub-TLV MUST be included if the ASBR has an IPv4 TE IPv4 TE Router ID sub-TLV MUST be included if the ASBR has an IPv4 TE
Router ID. If the ASBR does not have an IPv4 TE Router ID, the IPv6 Router ID. If the ASBR does not have an IPv4 TE Router ID, the IPv6
TE Router sub-TLV MUST be included instead. An IPv4 TE Router ID sub- TE Router sub-TLV MUST be included instead. An IPv4 TE Router ID sub-
TLV and IPv6 TE Router ID sub-TLV MAY both be present in an IS-IS TLV and IPv6 TE Router ID sub-TLV MAY both be present in an IS-IS
Router Capability TLV. Router Capability TLV.
3.3.5. IPv6 TE Router ID sub-TLV 3.3.5. IPv6 TE Router ID sub-TLV
The IPv6 TE Router ID sub-TLV is TLV type 12 (which needs to be The IPv6 TE Router ID sub-TLV is TLV type 12 (which needs to be
confirmed by IANA), and is four octets in length. The format of the confirmed by IANA see Section 6.3), and is four octets in length. The
IPv6 TE Router ID sub-TLV is as follows: format of the IPv6 TE Router ID sub-TLV is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | | Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TE Router ID | | TE Router ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| TE Router ID (continued) | | TE Router ID (continued) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 16, line 41 skipping to change at page 17, line 19
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V., [RFC3209] Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
Tunnels", RFC 3209, December 2001. Tunnels", RFC 3209, December 2001.
[ISIS] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and [ISIS] Callon, R., "Use of OSI IS-IS for routing in TCP/IP and
dual environments", RFC 1195, December 1990. dual environments", RFC 1195, December 1990.
[ISIS-TE] Smit, H. and T. Li, "Intermediate System to Intermediate
System (IS-IS) Extensions for Traffic Engineering (TE)",
draft-ietf-isis-te-bis-00.txt, {work in progress}.
[ISIS-TE-V3] Harrison, J., Berger, J., and Bartlett, M., "IPv6 [ISIS-TE-V3] Harrison, J., Berger, J., and Bartlett, M., "IPv6
Traffic Engineering in IS-IS", draft-ietf-isis-ipv6-te, Traffic Engineering in IS-IS", draft-ietf-isis-ipv6-te,
{work in progress}. {work in progress}.
[ISIS-CAP] Vasseur, J.P. et al., "IS-IS extensions for advertising [ISIS-CAP] Vasseur, J.P. et al., "IS-IS extensions for advertising
router information", RFC 4971, July 2007. router information", RFC 4971, July 2007.
8.2. Informative References 8.2. Informative References
[INTER-AS-TE-REQ] Zhang and Vasseur, "MPLS Inter-AS Traffic [INTER-AS-TE-REQ] Zhang and Vasseur, "MPLS Inter-AS Traffic
Engineering Requirements", RFC4216, November 2005. Engineering Requirements", RFC4216, November 2005.
[PD-PATH] Ayyangar, A., Vasseur, JP., and Zhang, R., "A Per-domain [PD-PATH] Ayyangar, A., Vasseur, JP., and Zhang, R., "A Per-domain
path computation method for establishing Inter-domain", path computation method for establishing Inter-domain", RFC
draft-ietf-ccamp-inter-domain-pd-path-comp, (work in 5152, February 2008.
progress).
[BRPC] JP. Vasseur, Ed., R. Zhang, N. Bitar, JL. Le Roux, "A Backward [BRPC] JP. Vasseur, Ed., R. Zhang, N. Bitar, JL. Le Roux, "A Backward
Recursive PCE-based Computation (BRPC) procedure to compute Recursive PCE-based Computation (BRPC) procedure to compute
shortest inter-domain Traffic Engineering Label Switched shortest inter-domain Traffic Engineering Label Switched
Paths ", draft-ietf-pce-brpc, (work in progress) Paths ", draft-ietf-pce-brpc, (work in progress)
[PCE] Farrel, A., Vasseur, JP., and Ash, J., "A Path Computation [PCE] Farrel, A., Vasseur, JP., and Ash, J., "A Path Computation
Element (PCE)-Based Architecture", RFC4655, August 2006. Element (PCE)-Based Architecture", RFC4655, August 2006.
[ISIS-TE] Smit, H. and T. Li, "Intermediate System to Intermediate
System (IS-IS) Extensions for Traffic Engineering (TE)",
RFC 3784, June 2004.
[GMPLS-TE] K.Kompella and Y.Rekhter, "IS-IS Extensions in Support of [GMPLS-TE] K.Kompella and Y.Rekhter, "IS-IS Extensions in Support of
Generalized Multi-Protocol Label Switching", RFC 4205, Generalized Multi-Protocol Label Switching", RFC 4205,
October 2005. October 2005.
[L1VPN-OSPF-AD] Bryskin, I., and Berger, L., "OSPF Based L1VPN Auto-
Discovery", draft-ietf-l1vpn-ospf-auto-discovery, (work in
progress).
[BGP] Rekhter, Li, Hares, "A Border Gateway Protocol 4 (BGP-4)", [BGP] Rekhter, Li, Hares, "A Border Gateway Protocol 4 (BGP-4)",
RFC4271, January 2006 RFC4271, January 2006
Authors' Addresses Authors' Addresses
Mach(Guoyi) Chen Mach(Guoyi) Chen
Huawei Technologies Co.,Ltd Huawei Technologies Co.,Ltd
KuiKe Building, No.9 Xinxi Rd., KuiKe Building, No.9 Xinxi Rd.,
Hai-Dian District Hai-Dian District
Beijing, 100085 Beijing, 100085
 End of changes. 34 change blocks. 
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