RFC 1387 (rfc1387) - Page 2 of 3

RIP Version 2 Protocol Analysis

RFC 1387                     RIP-2 Analysis                 January 1993


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,
   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 misinterpret 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".



Malkin