To discuss RIP also referred to as RIPng (Next Generation) for IPv6, a brief discussion of its predecessors, IPv4 RIP v1 and v2, will be necessary. Version 2 represents several enhancements to the original RIP standard. The most notable enhancement is the support for classless routing (also known as variable-length subnet masking, or VLSM), as well as authentication for RIP routing updates. Although two different versions exist, they are essentially the same protocol and share the same common characteristics, advantages, and flaws.

The Routing Information Protocol is one of the oldest and most stable dynamic routing protocols in use today. RIP s ancestry dates back as far as 1969 with its involvement in the original DARPANet project. RIP is a true open-standard, distance-vector protocol. Distance-vector protocols represent the first generation of dynamic-routing protocols.

Distance-vector protocols are based primarily on the Bellman-Ford algorithm, outlining many of the primary functions of such protocols. The Bellman-Ford algorithm gets its name from the individuals who developed the concept of distance-vector route calculation. This algorithm bases its metric calculation on a single-path tree concept, using the parameter of weight, and using a relaxation technique progressively throughout a path. This technique enables the protocol to select from several paths to a destination network, using a Boolean expression to determine the weight of a particular path and to select the path with the best metric. This is a very brief discussion of this process; a detailed discussion of the Bellman-Ford algorithm is outside the scope of...