Network Working Group G. Malkin Internet Draft Xylogics August 1992 RIP Version 2 Protocol Analysis Abstract As required by Routing Protocol Criteria (RFC 1264), this report documents the key features of the RIP-2 protocol and the current implementation experience. This report is a prerequisite to entering RIP-2 into the standards track. Status of this Memo This document is an Internet Draft. Internet Drafts are working documents of the Internet Engineering Task Force (IETF), its Areas, and its Working Groups. Note that other groups may also distribute working documents as Internet Drafts. Internet Drafts are draft documents valid for a maximum of six months. Internet Drafts may be updated, replaced, or obsoleted by other documents at any time. It is not appropriate to use Internet Drafts as reference material or to cite them other than as a "working draft" or "work in progress." Please check the I-D abstract listing contained in each Internet Draft directory to learn the current status of this or any other Internet Draft. It is intended that this document will be submitted to the IESG for consideration as a standards document. Distribution of this document is unlimited. Acknowledgements The RIP-2 protocol owes much to those who participated in the RIP-2 working group. A special thanks goes to Fred Baker for his help on the MIB, and to Jeffrey Honig for the implementation experience. Expiration: February 13, 1992 [Page 1] Internet Draft RIP-2 Analysis August 1992 1. Protocol Documents The RIP-2 protocol description is defined in Internet Draft "draft- ietf-malkin-rip-04.txt". This draft specifies an update to the "Routing Information Protocol" RFC 1058. The RIP-2 MIB description is defined in Internet Draft "draft-ietf- ripv2-mibext-02.txt". This draft has been approved by the Network Management Area Directorate, and has passed two independent MIB compiler checks. 2. Key Features While RIP-2 shares the same basic algorythms as RIP-1, it supports several new features. They are: routing domains, external route tags, subnet masks, next hop addresses, and authentication. 2.1 Routing Domains Routing domains allow multiple RIP "clouds" to exist over the same physical network. This is a feature requested by several members of the working group. It allows simple policies to be constructed by grouping routers into domains which share routing information. 2.2 External Route Tags The route tag field may be used to propagate information acquired from an EGP. The definition of the contents of this field are beyond the scope of this protocol. However, it may be used, for example, to propagate an EGP AS number. 2.3 Subnet Masks Inclusion of subnet masks was the original intent of opening the RIP protocol for improvement. Subnet mask information makes RIP more useful in a variety of environments and allows the use of variable subnet masks on the network. Subnet masks are also necessary for implementation of "classless" addressing, as the CIDR work proposes. 2.4 Next Hop Addresses Support for next hop addresses allows for optimization of routes in an environment which uses multiple routing protocols. For example, Expiration: February 13, 1992 [Page 2] Internet Draft RIP-2 Analysis August 1992 if RIP-2 were being run on a network along with another IGP, and one router ran both protocols, then that router could indicate to the other RIP-2 routers that a better next hop than itself exists for a given destination. 2.5 Authentication One significant improvement RIP-2 offers over RIP-1, is the addition of an authentication mechanism. Essentially, it is the same extensible mechanism provided by OSPF. Currently, only a plain-text password is defined for authentication. However, more sophisticated authentication schemes can easily be incorporated as they are defined. 2.6 Multicasting RIP-2 packets may be multicast instead of being broadcast. The use of an IP multicast address reduces the load on hosts which do not support routing protocols. It also allows RIP-2 routers to share information which RIP-1 routers cannot hear. This is useful since a RIP-1 router may missinterpret route information because it cannot apply the supplied subnet mask. 3. RIP-2 MIB The MIB for RIP-2 allows for monitoring and control of RIP's operation within the router. In addition to global and per-interface counters and controls, there is are per-peer counters which provide the status of RIP-2 "neighbors". 4. Implementations Currently, there is one nearly complete implementation of RIP-2. A "gated" implementation is now available with RIP-2, written by Jeffrey Honig at Cornell University. It may be acquired by anonymous FTP from gated.cornell.edu as pub/gated/gated-alpha.tar.Z. It implements multicasting, subnet masks, limited authentication, next- hop, and limited routing domain support. A RIP-2 version of ripquery is also available. The "gated" implementation does not yet support full subsumption rules, full authentication, full routing domains, and the MIB. It has been tested against itself and various RIP-1 implementations. A second, complete implementation is under development by a vendor Expiration: February 13, 1992 [Page 3] Internet Draft RIP-2 Analysis August 1992 who's identity cannot be disclosed at this time. 5. Security Security issues are discussed in section 2.5. 6. Author's Address Gary Scott Malkin Xylogics, Inc. 53 Third Avenue Burlington, MA 01803 Phone: (617) 272-8140 EMail: gmalkin@Xylogics.COM Expiration: February 13, 1992 [Page 4]