A method for implementing IP address announcement, comprising: adding, in a router, an announcement control switch for controlling Link-State Advertisement LSA 11 announcement and flooding; learning whether the announcement control switch of the router is currently in an announce state or a forward state by looking up a parameter configuration table; and performing, by the router according to a state of the announcement control switch, IP address announcement or IP address flooding for an IP address encapsulating LSA 11, wherein the method further comprises: before performing the IP address announcement, determining, by the router, whether a neighboring router has Opaque capability, whether the router has Opaque capability, and whether the announcement control switch set at the router is in the announce state; and confirming that the neighboring router has Opaque capability, the router has Opaque capability, and the announcement control switch set at the router is in the announce state; or before performing the IP address flooding, determining, by the router, whether the router has Opaque capability and whether the announcement control switch set at the router is in the forward state; and confirming that the router has Opaque capability and the announcement control switch set at the router is in the forward state. adding, in a router, an announcement control switch for controlling Link-State Advertisement LSA 11 announcement and flooding; learning whether the announcement control switch of the router is currently in an announce state or a forward state by looking up a parameter configuration table; and performing, by the router according to a state of the announcement control switch, IP address announcement or IP address flooding for an IP address encapsulating LSA 11, wherein the method further comprises: before performing the IP address announcement, determining, by the router, whether a neighboring router has Opaque capability, whether the router has Opaque capability, and whether the announcement control switch set at the router is in the announce state; and confirming that the neighboring router has Opaque capability, the router has Opaque capability, and the announcement control switch set at the router is in the announce state; or before performing the IP address flooding, determining, by the router, whether the router has Opaque capability and whether the announcement control switch set at the router is in the forward state; and confirming that the router has Opaque capability and the announcement control switch set at the router is in the forward state. before performing the IP address announcement, determining, by the router, whether a neighboring router has Opaque capability, whether the router has Opaque capability, and whether the announcement control switch set at the router is in the announce state; and confirming that the neighboring router has Opaque capability, the router has Opaque capability, and the announcement control switch set at the router is in the announce state; or before performing the IP address flooding, determining, by the router, whether the router has Opaque capability and whether the announcement control switch set at the router is in the forward state; and confirming that the router has Opaque capability and the announcement control switch set at the router is in the forward state.