Packet Guide to Routing and Switching

Chapter 5. Routing Information Protocol

Of course, in order to define which route is best, we have to have some way of measuring goodness.

RFC 1058

The Routing Information Protocol, or RIP, is an interior, distance vector protocol for small networks. It is defined in IETF RFCs 1058, 1388 and 1723. It was one of the first routing protocols used on the Internet. This protocol has been through two versions in order to handle classless address spaces. This chapter covers the protocol construction, operation and the content via packet capture. RFCs updating RIP to version 2 are circa 1998. Even at that time it was often held that RIP was an inferior routing protocol that had already had its fifteen minutes of fame. However, RIP still had fans. Quoting from RFC 2453:

With the advent of OSPF and IS-IS, there are those who believe that RIP is obsolete.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 ...