RIP Version 2 - Carrying Additional Information
RFC 1723
Document | Type |
RFC - Internet Standard
(November 1994; No errata)
Obsoleted by RFC 2453
Obsoletes RFC 1388
Updates RFC 1058
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Author | Gary Malkin | ||
Last updated | 2013-03-02 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 1723 (Internet Standard) | |
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | (None) | ||
Send notices to | (None) |
Network Working Group G. Malkin Request for Comments: 1723 Xylogics, Inc. Obsoletes: 1388 November 1994 Updates: 1058 Category: Standards Track RIP Version 2 Carrying Additional Information 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 specifies an extension of the Routing Information Protocol (RIP), as defined in [1,2], to expand the amount of useful information carried in RIP messages and to add a measure of security. This memo obsoletes RFC 1388, which specifies an update to the "Routing Information Protocol" STD 34, RFC 1058. The RIP-2 protocol analysis is documented in RFC 1721 [4]. The RIP-2 applicability statement is document in RFC 1722 [5]. The RIP-2 MIB description is defined in RFC 1724 [3]. This memo obsoletes RFC 1389. Acknowledgements I would like to thank the IETF ripv2 Working Group for their help in improving the RIP-2 protocol. Malkin [Page 1] RFC 1723 RIP Version 2 November 1994 Table of Contents 1. Justification . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Current RIP . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Protocol Extensions . . . . . . . . . . . . . . . . . . . . . . 3 3.1 Authentication . . . . . . . . . . . . . . . . . . . . . . . 4 3.2 Route Tag . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.3 Subnet Mask . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.4 Next Hop . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.5 Multicasting . . . . . . . . . . . . . . . . . . . . . . . . 5 3.6 Queries . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4. Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.1 Compatibility Switch . . . . . . . . . . . . . . . . . . . . 6 4.2 Authentication . . . . . . . . . . . . . . . . . . . . . . . 6 4.3 Larger Infinity . . . . . . . . . . . . . . . . . . . . . . . 7 4.4 Addressless Links . . . . . . . . . . . . . . . . . . . . . . 7 5. Security Considerations . . . . . . . . . . . . . . . . . . . . 7 Appendix A . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 9 1. Justification With the advent of OSPF and IS-IS, there are those who believe that RIP is obsolete. While it is true that the newer IGP routing protocols are far superior to RIP, RIP does have some advantages. Primarily, in a small network, RIP has very little overhead in terms of bandwidth used and configuration and management time. RIP is also very easy to implement, especially in relation to the newer IGPs. Additionally, there are many, many more RIP implementations in the field than OSPF and IS-IS combined. It is likely to remain that way for some years yet. Given that RIP will be useful in many environments for some period of time, it is reasonable to increase RIP's usefulness. This is especially true since the gain is far greater than the expense of the change. 2. Current RIP The current RIP message contains the minimal amount of information necessary for routers to route messages through a network. It also contains a large amount of unused space, owing to its origins. The current RIP protocol does not consider autonomous systems and IGP/EGP interactions, subnetting, and authentication since implementations of these postdate RIP. The lack of subnet masks is a Malkin [Page 2] RFC 1723 RIP Version 2 November 1994 particularly serious problem for routers since they need a subnet mask to know how to determine a route. If a RIP route is a network route (all non-network bits 0), the subnet mask equals the network mask. However, if some of the non-network bits are set, the router cannot determine the subnet mask. Worse still, the router cannot determine if the RIP route is a subnet route or a host route. Currently, some routers simply choose the subnet mask of the interface over which the route was learned and determine the route type from that. 3. Protocol Extensions This document does not change the RIP protocol per se. Rather, it provides extensions to the message format which allows routers toShow full document text