RIP Version 2 Protocol Applicability Statement (RFC1722)
Original Publication Date: 1994-Nov-01
Included in the Prior Art Database: 2000-Sep-12
Internet Society Requests For Comment (RFCs)
As required by Routing Protocol Criteria (RFC 1264), this report defines the applicability of the RIP-2 protocol within the Internet. This report is a prerequisite to advancing RIP-2 on the standards track.
Network Working Group G. Malkin
Request for Comments: 1722 Xylogics, Inc.
Category: Standards Track November 1994
RIP Version 2 Protocol Applicability Statement
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.
As required by Routing Protocol Criteria (RFC 1264), this report
defines the applicability of the RIP-2 protocol within the Internet.
This report is a prerequisite to advancing RIP-2 on the standards
1. Protocol Documents
The RIP-2 protocol analysis is documented in RFC 1721 .
The RIP-2 protocol description is defined in RFC 1723 . This memo
obsoletes RFC 1388, which specifies an update to the "Routing
Information Protocol" RFC 1058 (STD 34).
The RIP-2 MIB description is defined in RFC 1724 . This memo will
obsolete RFC 1389.
This report describes how RIP-2 may be useful within the Internet.
In essence, the environments in which RIP-2 is the IGP of choice is a
superset of the environments in which RIP-1, as defined in RFC 1058
, has traditionally been used. It is important to remember that
RIP-2 is an extension to RIP-1; RIP-2 is not a new protocol. Thus,
the operational aspects of distance-vector routing protocols, and
RIP-1 in particular, within an autonomous system are well understood.
It should be noted that RIP-2 is not intended to be a substitute for
OSPF in large autonomous systems; the restrictions on AS diameter and
complexity which applied to RIP-1 also apply to RIP-2. Rather, RIP-2
allows the smaller, simpler, distance-vector protocol to be used in
environments which require authentication or the use of variable
length subnet masks, but are not of a size or complexity which
require the use of the larger, more complex, link-state protocol.
The remainder of this report describes how each of the extensions to
RIP-1 may be used to increase the overall usefullness of RIP-2.
3. Extension Applicability
3.1 Subnet Masks
The original impetus behind the creation of RIP-2 was the desire to
include subnet masks in the routing information exchanged by RIP.
This was needed because subnetting was not defined when RIP was first
created. As long as the subnet mask was fixed for a network, and
well known by all the nodes on that network, a heuristic could be
used to determine if a route was a subnet route or a host route.
With the advent of variable length subnetting, CIDR, and
supernetting, it was no longer possible for a heuristic to reasonably
distinguish between network, subnet, and host routes.