Research And Implementation Of The Extension Way Of IBGP

As a protocol applied to exchange inter-domain routing information between autonomous systems, the Border Gateway Protocol (BGP) has been widely used. But the network topology has become more and more complex with the rapid expansion of the size of the network,so the traditional implementation of BGP could not meet the management and maintenance requirements of the network. In order to solve the CPU occupancy rate and the network issues such as increasing the possibility of instability with the network size increasing, IETF has proposed an extension way of IBGP-Route Reflection and Confederation mechanism. Route reflection was based on the idea that relaxing restrictions on routing information loop prevention mechanism to certain type of BGP. The approach that Confederation applied is to divide a large autonomous system into many small sub-autonomous systems. Both methods can reduce the number of IBGP sessions to a manageable level.This paper researches technical characteristics of BGP, elaborates the message formats used by BGP, four important path attributes, and the BGP routing selection rules. And the next, this paper discusses the technical characteristics of Route Reflection and Confederation mechanism after analyzing the problems of large-scale BGP network, and then designs and implements these mechanisms on the basis of theory studying. After that, this paper designs the system structure and key data structures, and elaborates the core processes of implementation. Experimental results show that using Route Reflection and Confederation mechanism as extension ways of IBGP can greatly reduce the number of IBGP sessions, forward routing information properly, and guarantee the stability of the network. So the design and realization of Route Reflection and Confederation mechanism are correct and feasible.