The invention discloses an information obtaining method and apparatus, and a router. The method comprises the following steps: sending first link requests to one or more adjacent routers supporting communication with a switching router, wherein the first link requests are used for requesting for a router link state advertisement (LSA) before switching; receiving router LSAs fed back by the one or more adjacent routers; determining whether the router LSAs meet preset conditions and obtaining a determination result; and under the condition that the determination result is that the router LSAs do not meet the preset conditions, according to the received router LSAs, obtaining adjacent router information of the switching router. Through the method, the problem of how to obtain neighbor information under the condition of no neighbor information after main/standby switching in prior art is solved.