draft-ietf-ccamp-ospf-interas-te-extension-02.txt   draft-ietf-ccamp-ospf-interas-te-extension-03.txt 
Network work group Mach Chen Network working group M. Chen
Internet Draft Renhai Zhang Internet Draft Renhai Zhang
Expires: May 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
November 19, 2007 April 10, 2008
OSPF Extensions in Support of Inter-AS Multiprotocol Label Switching OSPF 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-ospf-interas-te-extension-02.txt draft-ietf-ccamp-ospf-interas-te-extension-03.txt
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Abstract Abstract
This document describes extensions to the OSPF version 2 and 3 This document describes extensions to the OSPF version 2 and 3
protocols to support Multiprotocol Label Switching (MPLS) and protocols to support Multiprotocol Label Switching (MPLS) and
Generalized MPLS (GMPLS) Traffic Engineering(TE) for multiple Generalized MPLS (GMPLS) Traffic Engineering(TE) for multiple
Autonomous Systems (ASes). OSPF-TE v2 and v3 extensions are defined Autonomous Systems (ASes). OSPF-TE v2 and v3 extensions are defined
for the flooding of TE information about inter-AS links which can be for the flooding of TE information about inter-AS links which can be
used to perform inter-AS TE path computation. used to perform inter-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
1. Introduction.................................................2 1. Introduction.................................................3
2. Problem Statement............................................3 2. Problem Statement............................................3
2.1. A Note on Non-Objectives................................4 2.1. A Note on Non-Objectives................................4
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 OSPF...........................................7 3. Extensions to OSPF...........................................7
3.1. LSA Definitions.........................................8 3.1. LSA Definitions.........................................8
3.1.1. Inter-AS-TE-v2 LSA.................................8 3.1.1. Inter-AS-TE-v2 LSA.................................8
3.1.2. Inter-AS-TE-v3 LSA.................................8 3.1.2. Inter-AS-TE-v3 LSA.................................8
3.2. LSA Payload.............................................9 3.2. LSA Payload.............................................9
3.2.1. Link TLV...........................................9 3.2.1. Link TLV...........................................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.......................11 3.3.2. IPv4 Remote ASBR ID Sub-TLV.......................11
3.3.3. IPv6 Remote ASBR ID Sub-TLV.......................11 3.3.3. IPv6 Remote ASBR ID Sub-TLV.......................11
4. Procedure for Inter-AS TE Links.............................12 4. Procedure for Inter-AS TE Links.............................12
4.1. Origin of Proxied TE Information.......................13 4.1. Origin of Proxied TE Information.......................13
5. Security Considerations.....................................14 5. Security Considerations.....................................14
6. IANA Considerations.........................................14 6. IANA Considerations.........................................14
6.1. Inter-AS TE OSPF LSA...................................14 6.1. Inter-AS TE OSPF LSA...................................15
6.1.1. Inter-AS-TE-v2 LSA................................15
6.1.2. Inter-AS-TE-v3 LSA................................15
6.2. OSPF LSA Sub-TLVs type.................................15 6.2. OSPF LSA Sub-TLVs type.................................15
7. Acknowledgments.............................................15 7. Acknowledgments.............................................15
8. References..................................................15 8. References..................................................15
8.1. Normative References...................................15 8.1. Normative References...................................15
8.2. Informative References.................................16 8.2. Informative References.................................16
Authors' Addresses.............................................17 Authors' Addresses.............................................17
Intellectual Property Statement................................17 Intellectual Property Statement................................17
Disclaimer of Validity.........................................18 Disclaimer of Validity.........................................18
Copyright Statement............................................18 Copyright Statement............................................18
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Requirements for establishing Multiprotocol Label Switching Traffic Requirements for establishing Multiprotocol Label Switching Traffic
Engineering (MPLS-TE) Label Switched Paths (LSPs) that cross multiple Engineering (MPLS-TE) Label Switched Paths (LSPs) that cross multiple
Autonomous Systems (ASes) are described in [INTER-AS-TE-REQ]. As Autonomous Systems (ASes) are described in [INTER-AS-TE-REQ]. As
described in [INTER-AS-TE-REQ], a method SHOULD provide the ability described in [INTER-AS-TE-REQ], a method SHOULD provide the ability
to compute a path spanning multiple ASes. So a path computation to compute a path spanning multiple ASes. So a path computation
entity that may be the head-end Label Switching Router (LSR), an AS entity that may be the head-end Label Switching Router (LSR), an AS
Border Router (ASBR), or a Path Computation Element (PCE [PCE]) needs Border Router (ASBR), or a Path Computation Element (PCE [PCE]) needs
to know the TE information not only of the links within an AS, but to know the TE information not only of the links within an AS, but
also of the links that connect to other ASes. also of the links that connect to other ASes.
In this document, two new separate LSAs are defined to advertise In this document, two new separate Link State Advertisements (LSAs)
inter-AS TE information for OSPFv2 and OSPFv3 respectively, and three are defined to advertise inter-AS TE information for OSPFv2 and
new sub-TLVs are added to the existing Link TLV to extend TE OSPFv3 respectively, and three new sub-TLVs are added to the existing
capabilities for inter-AS Traffic Engineering. The detailed Link TLV to extend TE capabilities for inter-AS Traffic Engineering.
definitions and procedures are discussed in the following sections. The detailed definitions and procedures are discussed in the
following sections.
This document does not propose or define any mechanisms to advertise This document does not propose or define any mechanisms to advertise
any other extra-AS TE information within OSPF. See Section 2.1 for a any other extra-AS TE information within OSPF. See Section 2.1 for a
full list of non-objectives for this work. full list of non-objectives for this work.
2. Problem Statement 2. Problem Statement
As described in [INTER-AS-TE-REQ], in the case of establishing an As described in [INTER-AS-TE-REQ], in the case of establishing an
inter-AS TE LSP traversing multiple ASes, the Path message [RFC3209] inter-AS TE LSP traversing multiple ASes, the Path message [RFC3209]
may include the following elements in the Explicit Route Object (ERO) may include the following elements in the Explicit Route Object (ERO)
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The sections that follow examine how inter-AS TE link information The sections that follow examine how inter-AS TE link information
could be useful in both cases. could be useful in both cases.
2.1. A Note on Non-Objectives 2.1. A Note on Non-Objectives
It is important to note that this document does not make any change It is important to note that this document does not make any change
to the confidentiality and scaling assumptions surrounding the use of to the confidentiality and scaling assumptions surrounding the use of
ASes in the Internet. In particular, this document is conformant to ASes in the Internet. In particular, this document is conformant to
the requirements set out in [INTER-AS-TE-REQ]. the requirements set out in [INTER-AS-TE-REQ].
The following features are explicitly excluded.: The following features are explicitly excluded:
o There is no attempt to distribute TE information from within one o There is no attempt to distribute TE information from within one
AS to another AS. AS to another AS.
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.
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extensions address an entirely different problem from L1VPN Auto- extensions address an entirely different problem from L1VPN Auto-
Discovery [L1VPN-OSPF-AD] which defines how TE information about Discovery [L1VPN-OSPF-AD] which defines how TE information about
links between Customer Edge (CE) equipment and Provider Edge (PE) links between Customer Edge (CE) equipment and Provider Edge (PE)
equipment can be advertised in OSPF-TE alongside the auto-discovery equipment can be advertised in OSPF-TE alongside the auto-discovery
information for the CE-PE links. There is no overlap between this information for the CE-PE links. There is no overlap between this
document and [L1VPN-OSPF-AD]. 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 local 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
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(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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segments from the entry boundary nodes that provide connection from segments from the entry boundary nodes that provide connection from
AS2 to the destination (R12). But, to provide suitable path segments, AS2 to the destination (R12). But, to provide suitable path segments,
PCE3 must determine which entry boundary nodes provide connectivity PCE3 must determine which entry boundary nodes provide connectivity
to its upstream neighbor AS (identified by its AS number), and must to its upstream neighbor AS (identified by its AS number), and must
know the TE properties of the inter-AS TE links. In the same way, know the TE properties of the inter-AS TE links. In the same way,
PCE2 also needs to determine the entry boundary nodes according to PCE2 also needs to determine the entry boundary nodes according to
its upstream 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. The AS number of the information listed in Section 2.2 is required. The AS number of the
neighboring AS connected to by each inter-AS TE link is particular neighboring AS connected to by each inter-AS TE link is particularly
important. important.
3. Extensions to OSPF 3. Extensions to OSPF
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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the Inter-AS-TE-v2 LSA, is defined in this document. The Inter-AS-TE- the Inter-AS-TE-v2 LSA, is defined in this document. The Inter-AS-TE-
v2 LSA has the same format as "Traffic Engineering LSA" which is v2 LSA has the same format as "Traffic Engineering LSA" which is
defined in [OSPF-TE]. defined in [OSPF-TE].
The inter-AS TE link advertisement SHOULD be carried in a Type 10 The inter-AS TE link advertisement SHOULD be carried in a Type 10
Opaque LSA if the flooding scope is to be limited to within the Opaque LSA if the flooding scope is to be limited to within the
single IGP area to which the ASBR belongs, or MAY be carried in a single IGP area to which the ASBR belongs, or MAY be carried in a
Type 11 Opaque LSA if the information is intended to reach all Type 11 Opaque LSA if the information is intended to reach all
routers (including area border routers, ASBRs, and PCEs) in the AS. routers (including area border routers, ASBRs, and PCEs) in the AS.
The choice between the use of a Type 10 or Type 11 Opaque LSA is a The choice between the use of a Type 10 or Type 11 Opaque LSA is a
network-wide policy choice, and configuration control of it SHOULD be AS-wide policy choice, and configuration control of it SHOULD be
provided in ASBR implementations that support the advertisement of provided in ASBR implementations that support the advertisement of
inter-AS TE links. inter-AS TE links.
The Link State ID of an Opaque LSA as defined in [RFC2370] is divided The Link State ID of an Opaque LSA as defined in [RFC2370] is divided
into two parts. One of them is the Opaque type (8-bit), the other is into two parts. One of them is the Opaque type (8-bit), the other is
the Opaque ID (24-bit). The suggested value for the Opaque type of the Opaque ID (24-bit). The suggested value for the Opaque type of
Inter-AS-TE-v2 LSA is TBD and will be assigned by IANA (see Section Inter-AS-TE-v2 LSA is TBD and will be assigned by IANA (see Section
6.1). We suggest the value 6. The Opaque ID (in this document called 6.1). We suggest the value 6. The Opaque ID (in this document called
the Instance) of the Inter-AS-TE-v2 LSA is an arbitrary value used to the Instance) of the Inter-AS-TE-v2 LSA is an arbitrary value used to
uniquely identify Traffic Engineering LSAs. The Link State ID has no uniquely identify Traffic Engineering LSAs. The Link State ID has no
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used to uniquely identify Traffic Engineering LSAs. The LSA ID has no used to uniquely identify Traffic Engineering LSAs. The LSA ID has no
topological significance. topological significance.
The TLVs with the body of an Inter-AS-TE-v3 LSA have the same format The TLVs with the body of an Inter-AS-TE-v3 LSA have the same format
and semantic as defined above in [OSPF-V3-TE]. New sub-TLVs and semantic as defined above in [OSPF-V3-TE]. New sub-TLVs
specifically for inter-AS TE Link advertisement are described in specifically for inter-AS TE Link advertisement are described in
Section 3.2. Section 3.2.
3.2. LSA Payload 3.2. LSA Payload
Both Inter-AS-TE-v2 LSA and Inter-AS-TE-v3 LSA contain one top level Both the Inter-AS-TE-v2 LSA and Inter-AS-TE-v3 LSA contain one top
TLV: level TLV:
2 - Link TLV 2 - Link TLV
For the Inter-AS-TE-v2 LSA this TLV is defined in [OSPF-TE] and for For the Inter-AS-TE-v2 LSA this TLV is defined in [OSPF-TE] and for
the Inter-AS-TE-v3 LSA this TLV is defined in [OSPF-V3-TE]. The sub- the Inter-AS-TE-v3 LSA this TLV is defined in [OSPF-V3-TE]. The sub-
TLVs carried in this TLV are described in the following sections. TLVs carried in this TLV are described in the following sections.
3.2.1. Link TLV 3.2.1. Link TLV
The Link TLV describes a single link and consists a set of sub-TLVs. The Link TLV describes a single link and consists a set of sub-TLVs.
The sub-TLVs for inclusion in the Link TLV of the Inter-AS-TE-v2 LSA The sub-TLVs for inclusion in the Link TLV of the Inter-AS-TE-v2 LSA
and Inter-AS-TE-v3 LSA are defined respectively in [OSPF-TE] and and Inter-AS-TE-v3 LSA are defined respectively in [OSPF-TE] and
[OSPF-V3-TE] and the list of sub-TLVs may be extended by other [OSPF-V3-TE] and the list of sub-TLVs may be extended by other
documents. However, this document defines one exception as follows. documents. However, this document defines one exception as follows.
The Link ID sub-TLV [OSPF-TE] MUST NOT be used in the Link TLV of an The Link ID sub-TLV [OSPF-TE] MUST NOT be used in the Link TLV of an
Inter-AS-TE-v2 LSA, and the Neighbor ID sub-TLV [OSPF-V3-TE] MUST NOT Inter-AS-TE-v2 LSA, and the Neighbor ID sub-TLV [OSPF-V3-TE] MUST NOT
be used in the Link TLV of an Inter-AS-TE-v3 LSA. This is because the be used in the Link TLV of an Inter-AS-TE-v3 LSA. Given that OSPF is
address of the link-end or neighbor is an address in another AS that an IGP and should only be utilized between routers in the same
may operate a different address space; such an address is of no value routing domain, the OSPF specific Link ID and Neighbor ID sub-TLVs
to routing within the AS where this Link TLV is used. are not applicable to inter-AS links.
Instead, the remote ASBR is identified by the inclusion of the Instead, the remote ASBR is identified by the inclusion of the
following new sub-TLVs defined in this document and described in the following new sub-TLVs defined in this document and described in the
subsequent sections. subsequent sections.
21 - Remote AS Number sub-TLV 21 - Remote AS Number sub-TLV
22 - IPv4 Remote ASBR ID sub-TLV 22 - IPv4 Remote ASBR ID sub-TLV
23 - IPv6 Remote ASBR ID sub-TLV 23 - IPv6 Remote ASBR ID sub-TLV
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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 Link TLV when advertising inter-AS links. The Remote AS Number in the Link TLV when advertising inter-AS links. The Remote AS Number
sub-TLV specifies the AS number of the neighboring AS to which the sub-TLV specifies the AS number of the neighboring AS to which the
advertised link connects. The Remote AS number sub-TLV is REQUIRED in advertised link connects. The Remote AS number sub-TLV is REQUIRED in
a Link TLV that advertises an inter-AS TE link. a Link TLV that advertises an inter-AS TE link.
The Remote AS number sub-TLV is TLV type 21 (which needs to be The Remote AS number sub-TLV is TLV type 21 (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
used for the AS number, as in current deployments, the left (high- used for the AS number, as in current deployments, the left (high-
order) two octets MUST be set to zero. order) two octets MUST be set to zero.
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, can be included in the Link TLV when advertising inter-AS links. TLV, can be included in the Link TLV when advertising inter-AS links.
The IPv4 Remote ASBR ID sub-TLV specifies the IPv4 identifier of the The IPv4 Remote ASBR ID sub-TLV specifies the IPv4 identifier of the
remote ASBR to which the advertised inter-AS link connects. This remote ASBR to which the advertised inter-AS link connects. This
could be any stable and routable IPv4 address of the remote ASBR. Use could be any stable and routable IPv4 address of the remote ASBR. Use
of the TE Router ID is RECOMMENDED. of the TE Router Address TE Router ID as specified in the Router
Address TLV [OSPF-TE] is RECOMMENDED.
The IPv4 Remote ASBR ID sub-TLV is TLV type 22 (which needs to be The IPv4 Remote ASBR ID sub-TLV is TLV type 22 (which needs to be
confirmed by IANA), and is four octets in length. Its format is as confirmed by IANA see Section 6.2), and is four octets in length. Its
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 ASBR ID | | Remote ASBR ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
In OSPFv2 advertisements, the IPv4 Remote ASBR ID sub-TLV MUST be In OSPFv2 advertisements, the IPv4 Remote ASBR ID sub-TLV MUST be
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An IPv4 Remote ASBR ID sub-TLV and IPv6 Remote ASBR ID sub-TLV MAY An IPv4 Remote ASBR ID sub-TLV and IPv6 Remote ASBR ID sub-TLV MAY
both be present in a Link TLV in OSPFv2 or OSPFv3. both be present in a Link TLV in OSPFv2 or OSPFv3.
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, can be included in the Link TLV when advertising inter-AS links. TLV, can be included in the Link TLV when advertising inter-AS links.
The IPv6 Remote ASBR ID sub-TLV specifies the identifier of the The IPv6 Remote ASBR ID sub-TLV specifies the identifier of the
remote ASBR to which the advertised inter-AS link connects. This remote ASBR to which the advertised inter-AS link connects. This
could be any stable, routable and global IPv6 address of the remote could be any stable, routable and global IPv6 address of the remote
ASBR. Use of the TE Router ID is RECOMMENDED. ASBR. Use of the TE Router IPv6 Address IPv6 TE Router ID as
specified in the IPv6 Router Address as specified in the IPv6 Router
Address TLV [OSPF-V3-TE] is RECOMMENDED.
The IPv6 Remote ASBR ID sub-TLV is TLV type 23 (which needs to be The IPv6 Remote ASBR ID sub-TLV is TLV type 23 (which needs to be
confirmed by IANA), and is sixteen octets in length. Its format is as confirmed by IANA see Section 6.2), and is sixteen octets in length.
follows: Its 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 ASBR ID | | Remote ASBR ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Remote ASBR ID (continued) | | Remote ASBR ID (continued) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 12, line 36 skipping to change at page 12, line 39
included if the neighboring ASBR has an IPv6 address. If the included if the neighboring ASBR has an IPv6 address. If the
neighboring ASBR does not have an IPv6 address, the IPv4 Remote ASBR neighboring ASBR does not have an IPv6 address, the IPv4 Remote ASBR
ID sub-TLV MUST be included instead. An IPv4 Remote ASBR ID sub-TLV ID sub-TLV MUST be included instead. An IPv4 Remote ASBR ID sub-TLV
and IPv6 Remote ASBR ID sub-TLV MAY both be present in a Link TLV in and IPv6 Remote ASBR ID sub-TLV MAY both be present in a Link TLV in
OSPFv2 or OSPFv3. OSPFv2 or OSPFv3.
4. Procedure for Inter-AS TE Links 4. Procedure for Inter-AS TE Links
When TE is enabled on an inter-AS link and the link is up, the ASBR When TE is enabled on an inter-AS link and the link is up, the ASBR
SHOULD advertise this link using the normal procedures for OSPF-TE SHOULD advertise this link using the normal procedures for OSPF-TE
[OSPF-TE]. When either the link is down or TE is disabled on the [OSPF-TE]. When either the link is down or TE is disabled on the link,
link , the ASBR SHOULD withdraw the advertisement. When there are the ASBR SHOULD withdraw the advertisement. When there are changes to
changes to the TE parameters for the link (for example, when the the TE parameters for the link (for example, when the available
available bandwidth changes) the ASBR SHOULD re-advertise the link, bandwidth changes) the ASBR SHOULD re-advertise the link, but the
but the ASBR MUST take precautions against excessive re- ASBR MUST take precautions against excessive re-advertisements as
advertisements as described in [OSPF-TE]. described in [OSPF-TE].
Hellos MUST NOT be exchanged over the inter-AS link, and Hellos MUST NOT be exchanged over the inter-AS link, and consequently,
consequently , an OSPF adjacency MUST NOT be formed. an OSPF adjacency MUST NOT be formed.
The information advertised comes from the ASBR's knowledge of the TE The information advertised comes from the ASBR's knowledge of the TE
capabilities of the link, the ASBR's knowledge of the current status capabilities of the link, the ASBR's knowledge of the current status
and usage of the link, and configuration at the ASBR of the remote AS and usage of the link, and configuration at the ASBR of the remote AS
number and remote ASBR TE Router ID. number and remote ASBR TE Router ID.
Legacy routers receiving an advertisement for an inter-AS TE link are Legacy routers receiving an advertisement for an inter-AS TE link are
able to ignore it because the Link Type carries an unknown value. able to ignore it because the Link Type carries an unknown value.
They will continue to flood the LSA, but will not attempt to use the They will continue to flood the LSA, but will not attempt to use the
information received as if the link were an intra-AS TE link. information received as if the link were an intra-AS TE link.
skipping to change at page 14, line 46 skipping to change at page 15, line 7
exchange TE information as described in Section 4.1, the inter-AS BGP exchange TE information as described in Section 4.1, the inter-AS BGP
session will need to be fully secured. session will need to be fully secured.
6. IANA Considerations 6. IANA Considerations
IANA is requested to make the following allocations from registries IANA is requested to make the following allocations from registries
under its control. under its control.
6.1. Inter-AS TE OSPF LSA 6.1. Inter-AS TE OSPF LSA
6.1.1. Inter-AS-TE-v2 LSA
IANA is requested to assign a new Opaque LSA type (TBD) to Inter-AS- IANA is requested to assign a new Opaque LSA type (TBD) to Inter-AS-
TE-v2 LSA and a new OSPFv3 LSA type function code (TBD) to Inter-AS- TE-v2 LSA. We suggest that the value 6 be assigned for the new Opaque
TE-v3 LSA. We suggest that the value 6 be assigned for the new Opaque LSA type.
LSA type, and the value 11 be assigned for the new OSPV3 LSA type
function code. 6.1.2. Inter-AS-TE-v3 LSA
IANA is requested to assign a new OSPFv3 LSA type function code (TBD)
to Inter-AS-TE-v3 LSA. We suggest that the value 11 be assigned for
the new OSPV3 LSA type function code.
6.2. OSPF LSA Sub-TLVs type 6.2. OSPF LSA Sub-TLVs type
IANA maintains the "Open Shortest Path First (OSPF) Traffic IANA maintains the "Open Shortest Path First (OSPF) Traffic
Engineering TLVs" registry with sub-registry "Types for sub-TLVs in a Engineering TLVs" registry with sub-registry "Types for sub-TLVs in a
TE Link TLV". IANA is requested to assign a new sub-TLV as follows. TE Link TLV". IANA is requested to assign three new sub-TLVs as
The following number are suggested (see section 3.3): follows. The following numbers are suggested (see section 3.3):
Value Meaning Value Meaning
21 Remote AS Number sub-TLV 21 Remote AS Number sub-TLV
22 IPv4 Remote ASBR ID sub-TLV 22 IPv4 Remote ASBR ID sub-TLV
23 IPv6 Remote ASBR ID sub-TLV 23 IPv6 Remote ASBR ID sub-TLV
7. Acknowledgments 7. Acknowledgments
skipping to change at page 16, line 18 skipping to change at page 16, line 31
[OSPFV3] Coltun, R., Ferguson, D., and J. Moy, "OSPF for IPv6", [OSPFV3] Coltun, R., Ferguson, D., and J. Moy, "OSPF for IPv6",
RFC 2740, April 1998. RFC 2740, April 1998.
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.
[OSPFV3] Coltun, R., Ferguson, D., and J. Moy, "OSPF for IPv6", RFC
2740, April 1998.
[L1VPN-OSPF-AD] Bryskin, I., and Berger, L., "OSPF Based L1VPN Auto- [L1VPN-OSPF-AD] Bryskin, I., and Berger, L., "OSPF Based L1VPN Auto-
Discovery", draft-ietf-l1vpn-ospf-auto-discovery, (work in Discovery", draft-ietf-l1vpn-ospf-auto-discovery, (work in
progress). 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 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
P.R. China P.R. China
Email: mach@huawei.com Email: mach@huawei.com
Renhai Zhang Renhai Zhang
Huawei Technologies Co.,Ltd Huawei Technologies Co.,Ltd
skipping to change at page 18, line 23 skipping to change at page 18, line 23
This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement Copyright Statement
Copyright (C) The IETF Trust (2007). Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors contained in BCP 78, and except as set forth therein, the authors
retain all their rights. retain all their rights.
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