RIP Version 2 Protocol Applicability Statement (RFC1722)
Original Publication Date: 1994-Nov-01
Included in the Prior Art Database: 2019-Feb-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. [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 track.
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
Malkin [Page 1]
RFC 1722 RIP-2 Applicability November 1994
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.
By using the 32-bit field immediately following the IP address in a RIP routing entry, it became possible to positively identify a route’s type....