Route Redistribution Between BGP and IGPs
As you are aware, a router running the BGP routing protocol handles its own routing table separately from the IP routing table. An AS uses three primary methods to inject route information into BGP: using the network command, redistributing static routes to null 0, and redistributing dynamic routes into BGP.
Using the network Command
First, the network command is used to manually configure BGP to advertise a network that already exists in the IP routing table. The list of network command entries must contain all the networks in the AS that you want to advertise. For example:
RouterA(config) router bgp 65410 RouterA(config-router)# network 192.168.10.0 RouterA(config-router)# network 10.10.0.0
If summary ...