Network Working Group B. Thomas
Request for Comments: 5561 K. Raza
Updates: 5036 Cisco Systems, Inc.
Category: Standards Track S. Aggarwal
R. Aggarwal
Juniper Networks
JL. Le Roux
France Telecom
July 2009
LDP Capabilities
Abstract
A number of enhancements to the Label Distribution Protocol (LDP)
have been proposed. Some have been implemented, and some are
advancing toward standardization. It is likely that additional
enhancements will be proposed in the future. This document defines a
mechanism for advertising LDP enhancements at session initialization
time, as well as a mechanism to enable and disable enhancements after
LDP session establishment.
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
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Without obtaining an adequate license from the person(s) controlling
Thomas, et al. Standards Track [Page 1]RFC 5561 LDP Capabilities July 2009
the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may
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it for publication as an RFC or to translate it into languages other
than English.
Table of Contents
1. Introduction ....................................................2
1.1. Conventions Used in This Document ..........................3
2. The LDP Capability Mechanism ....................................3
2.1. Capability Document ........................................4
3. Specifying Capabilities in LDP Messages .........................4
3.1. Backward Compatibility TLVs ................................6
4. Capability Message ..............................................6
5. Note on Terminology .............................................7
6. Procedures for Capability Parameters in Initialization
Messages ........................................................7
7. Procedures for Capability Parameters in Capability Messages .....8
8. Extensions to Error Handling ....................................9
9. Dynamic Capability Announcement TLV .............................9
10. Backward Compatibility ........................................10
11. Security Considerations .......................................10
12. IANA Considerations ...........................................11
13. Acknowledgments ...............................................11
14. References ....................................................11
14.1. Normative References .....................................11
14.2. Informative References ...................................11
1. Introduction
A number of enhancements to LDP as specified in [RFC5036] have been
proposed. These include LDP Graceful Restart [RFC3478], Fault
Tolerant LDP [RFC3479], multicast extensions [MLDP], signaling for
Layer 2 circuits [RFC4447], a method for learning labels advertised
by next-next-hop routers in support of fast reroute node protection
[NNHOP], upstream label allocation [UPSTREAM_LDP], and extensions for
signaling inter-area Label Switched Paths (LSPs) [RFC5283]. Some
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