Efficient method of collecting routing tables based on OSPF/iBGP monitoring

If a problem with IP communication occurs, IP network operators refer to the routing tables of the affected routers to check the routes to the destinations. There are a number of methods currently used for referring to routing tables. However, operators cannot refer to past routing tables using existing methods. The past routing tables are useful for IP network operation. For example, operators can find out how the influence of a network problem on routes spreads to the network by checking fluctuations in each routerpsilas routing table. In this paper, we propose a method of collecting every routerpsilas routing table within a domain based on the monitoring of routing protocols. In our method, we collect routing protocol messages and calculate all routerspsila routing tables within a domain in a concentrated manner using the same way where each router within a domain calculates its routing table. Routing tables are calculated whenever route status in IP networks changes, and calculated routing tables are stored so that operators can refer to them at any time in the future.