The present disclosure describes reducing flooding of link state information of a link state protocol in a network with multiple routers. A filtering strategy is pre-configured on a router interface for filtering link state information generated by a first router. The filtering strategy is to enable link state database (LSDB) isolation between a second router associated with the router interface and the first router. Link state information generated by the first router is received or sent according to the pre-configured filtering strategy via the router interface.