Study And Realization Of OSPF Graceful Restart Protocol

OSPF(open shortest path first)is a kind of link-state internal gateway protocol and designed specially for Internet. OSPF recalculates routes quickly in the face of topological changes, utilizing the minimum of routing protocol traffic. So it is used widely in Internet. OSPF graceful restart protocol, an implementation to OSPF, has the function of maintaining the data forwarding capability in the process of the OSPF being restarted in the router. This thesis is about how to realize the OSPF graceful restart. And the main jobs done are as follows: The theory of OSPF and OSPF graceful restart is introduced and important processing flows in these protocols are analyzed. BesIDes, the difference and comparation of those two protocols are made.On the ground of the profound research of OSPF routing software module, the relationship between OSPF and other modules in router is made clear and important processing flows and data structure in implementation are concluded as well. The detailed design of OSPF graceful restart protocol is realized and the details of the whole implementation procedure is introduced. Meanwhile, some of the important processing flow is described by pseudo code and the key data structures are listed. OSPF graceful restart was tested and realized in X X series of routers, which greatly improves the stability and maintainability of router and increases their competitive ability.