OSPF Applicability: Applicability Statement for OSPF
Requirements for router vendors claiming conformance to the OSPF applicability statement.
Internet Architecture Board and L. Chapin, "Applicability Statement for OSPF", RFC 1370, DOI 10.17487/RFC1370, October 1992, <https://www.rfc-editor.org/info/rfc1370>.
@misc{rfc1370,
series = {Request for Comments},
number = 1370,
howpublished = {RFC 1370},
publisher = {RFC Editor},
doi = {10.17487/RFC1370},
url = {https://www.rfc-editor.org/info/rfc1370},
author = {Internet Architecture Board and L. Chapin},
title = {{Applicability Statement for OSPF}},
pagetotal = 2,
year = 1992,
month = oct,
} RFC text
Contents
Network Working Group Internet Architecture Board
Request for Comments: 1370 Lyman Chapin, Chair
October 1992
Applicability Statement for OSPF
Status of this Memo
This memo is an IAB standards track Applicability Statement for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "IAB
Official Protocol Standards" for the standardization state and status
of this specification. Distribution of this memo is unlimited.
1. INTRODUCTION
Users and vendors have expressed a strong need for IP routers from
different vendors that can interoperate using a common Interior
Gateway Protocol (IGP). There is therefore an urgent requirement for
a high-functionality non-proprietary 'open' IGP that will be
ubiquitously available from all IP router vendors.
The Open Shortest Path First (OSPF) routing protocol [1] was
developed by the IETF to fill this need. This Applicability
Statement specifies the circumstances under which OSPF must be
implemented by router vendors. The history of OSPF development and
the reasoning behind this Applicability Statement will be found in
[5].
This Applicability Statement places a requirement on vendors claiming
conformance to this standard, in order to assure that users will have
the option of deploying OSPF when they need a multivendor,
interoperable IGP in their environment. Users are of course free to
use whatever routing protocol best meets their requirements.
2. APPLICABILITY OF OSPF
An IP router that implements any routing protocol (other than static
routes) is required to implement OSPF [1] and the OSPF MIB [2].
Within OSPF, implementation of all features except TOS (Type-of-
Service) routing is required; implementation of TOS routing is
recommended.
This requirement does not prevent a router from implementing other
routing protocols in addition to OSPF. Complete and definitive
requirements on all aspects of an IP router will be found in a
forthcoming Applicability Statement: "Requirements for IP Routers"
[4], currently in preparation in the IETF. "Requirements for IP
Routers", when it becomes a Standard, will take precedence if its
requirements for OSPF should conflict with this present RFC.
It should be noted that OSPF is intended for use by routers for
exchanging dynamic routing information, and not for use by hosts. As
discussed in Section 3.3.1.4 of STD-2, "Requirements for Internet
Hosts -- Communication Layers" [3], 'wiretapping' of routing
protocols by hosts is not recommended. Recommended mechanisms for a
host to use for discovering local routers and detecting dead routers
will be found in [3]. In particular, the ICMP Router Discovery
messages, under development, will provide a standard way for a host
to learn the addresses of local routers [6].
3. REFERENCES
[1] Moy, J., "OSPF Version 2", RFC 1247, Proteon, Inc., July 1991.
[2] Baker, F., and R. Coltun, "OSPF Version 2 Management Information
Base", RFC 1253, ACC, Computer Science Center, August 1991.
[3] Braden, R., Editor, "Requirements for Internet Hosts --
Communication Layers", IETF, STD 3, RFC 1122, October 1989.
[4] Almquist, P., Editor, "Requirements for IP Routers", Work in
Preparation, IETF.
[5] Gross, P., Editor, "Choosing a "Common IGP" for the IP Internet
(The IESG's Recommendation to the IAB)", RFC 1371, IESG, October
1992.
[6] Deering, S., Editor, "ICMP Router Discovery Messages", RFC 1256,
Xerox PARC, September 1991.
Security Considerations
Security issues are not discussed in this memo.
Author's Address
A. Lyman Chapin
BBN Communications Corporation
150 Cambridge Park Drive
Cambridge, MA 02140
Phone: 617-873-3133
Fax: 617-873-4086
Email: Lyman@BBN.COM
ISO Plain Language
On this page
§1The Need for a Common IGP
The Internet Architecture Board says users and vendors wanted IP routers from different vendors to interoperate through a common Interior Gateway Protocol (IGP). The IETF developed Open Shortest Path First (OSPF) to meet that need as a non-proprietary protocol.
This applicability statement sets requirements for vendors claiming conformance. It does not require users to choose OSPF; they remain free to use the routing protocol that best meets their needs.
Different router makers needed a shared way to exchange routes. This memo sets a minimum OSPF requirement for routers that support routing.
§2Router Implementation Requirements
An IP router that implements any routing protocol other than static routes is required to implement OSPF and the OSPF Management Information Base. Within OSPF, all features except Type-of-Service routing are required; Type-of-Service routing is recommended.
The requirement does not prevent a router from implementing other protocols too. The memo says broader requirements for IP routers were being prepared and would take precedence if they later conflicted with this statement.
A router that supports routing must include OSPF and its management information. It may support other routing protocols as well.
§2Routers, Not Hosts
OSPF is intended for routers exchanging dynamic routing information, not for hosts. The memo discourages hosts from listening in on routing protocols and points to host requirements and ICMP Router Discovery as ways for a host to learn about local routers.
The security considerations section says security issues are not discussed in this memo.
OSPF is for routers to share route information. A host should use host-specific methods to discover its local router.