Eigrp Protocol Analysis And Software Analysis

At present, there are two types IGP(interior gateway protocol)widely used in the network: RIP(routing information protocol) and OSPF(open shortest path first). RIP bases on distance vector algorithm and OSPF bases on link state algorithm. They both have many advantages, they also have some defects. RIP is very simple and easy to configure, but its convergence time is slow, so it is not fit for big network. As for OSPF, its convergence is very quick, but it is very complicated and it needs many more resource of router. So cisco company puts forward to EIGRP(enhanced interior gateway routing protocol), it takes in the advantages of RIP and OSPF. Now EIGRP is widely used in cisco router. So it is very important to study its advantages and performance.This article mainly discusses DUAL(diffusing update algorithm)which is the kernel algorithm of EIGRP. and from software analysis aspect describe its advantages: simple mechanism, small using the router's resource, quick convergence, loop-free route. At first, the article introduces some concepts of EIGRP and something detail about DUAL, such as: EIGRP metrics, successor, feasible successor, feasible distance, feasible condition. We also compare EIGRP with RIP and OSPF to demonstrate which is the advantage of EIGRP. Then mainly discuss how to embody these advantages on the VxWorks platform. The article discuss about the system interface part of the software: the process of sending and receiving the EIGRP packet, the command process from the configure shell process, the show process of the EIGRP, the adding and deleting route process and so on. At last, we test it according to test topology graph. From the result, we can see this software has the most functions of EIGRP, and can communicate with the cisco router and exchange the router information.