Network Working Group L. Berger
Request for Comments: 5250 LabN
Obsoletes: 2370 I. Bryskin
Category: Standards Track Adva
A. Zinin
Alcatel-Lucent
R. Coltun
Acoustra Productions
July 2008
The OSPF Opaque LSA Option
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.
Abstract
This document defines enhancements to the OSPF protocol to support a
new class of link state advertisements (LSAs) called Opaque LSAs.
Opaque LSAs provide a generalized mechanism to allow for the future
extensibility of OSPF. Opaque LSAs consist of a standard LSA header
followed by application-specific information. The information field
may be used directly by OSPF or by other applications. Standard OSPF
link-state database flooding mechanisms are used to distribute Opaque
LSAs to all or some limited portion of the OSPF topology.
This document replaces RFC 2370 and adds to it a mechanism to enable
an OSPF router to validate Autonomous System (AS)-scope Opaque LSAs
originated outside of the router's OSPF area.
Berger, et al. Standards Track [Page 1]
RFC 5250 OSPF Opaque LSA Option July 2008
Table of Contents
1. Introduction ....................................................3
1.1. Organization of This Document ..............................3
1.2. Acknowledgments ............................................3
2. Conventions Used in This Document ...............................4
3. The Opaque LSA ..................................................4
3.1. Flooding Opaque LSAs .......................................5
3.2. Modifications to the Neighbor State Machine ................6
4. Protocol Data Structures ........................................7
4.1. Additions to the OSPF Neighbor Structure ...................8
5. Inter-Area Considerations .......................................8
6. Management Considerations .......................................9
7. Backward Compatibility ..........................................9
8. Security Considerations .........................................9
9. IANA Considerations ............................................11
10. References ....................................................12
10.1. Normative References .....................................12
10.2. Informative References ...................................12
Appendix A. OSPF Data formats .....................................13
A.1. The Options Field .........................................13
A.2. The Opaque LSA ............................................14
Berger, et al. Standards Track [Page 2]
RFC 5250 OSPF Opaque LSA Option July 2008
1. Introduction
Over the last several years, the OSPF routing protocol [OSPF] has
been widely deployed throughout the Internet. As a result of this
deployment and the evolution of networking technology, OSPF has been
extended to support many options; this evolution will obviously
continue.
This document defines enhancements to the OSPF protocol to support a
new class of link state advertisements (LSAs) called Opaque LSAs.
Opaque LSAs provide a generalized mechanism to allow for the future
extensibility of OSPF. The information contained in Opaque LSAs may
be used directly by OSPF or indirectly by some application wishing to
distribute information throughout the OSPF domain. The exact use of
Opaque LSAs is beyond the scope of this document.
Opaque LSAs consist of a standard LSA header followed by a 32-bit
aligned application-specific information field. Like any other LSA,
the Opaque LSA uses the link-state database distribution mechanism
for flooding this information throughout the topology. The link-
state type field of the Opaque LSA identifies the LSA's range of
topological distribution. This range is referred to as the flooding
datatracker.ietf.org