Patent ID: 8154992

Claim:
A router, comprising: a primary control plane running one or more routing processes; a secondary control plane interconnected with the primary control plane; wherein the primary control plane periodically transmits synchronization signals indicating a forwarding state of the primary control plane to the secondary control plane, and the secondary control plane updates its state based on the synchronization signals; wherein the synchronization signals are transmitted with a corresponding sequence number and the secondary control plane is capable of detecting that it did not receive a signal based on the sequence number of a received signal; and wherein in the event that the primary control plane fails, the secondary control plane: takes over the routing processes of the primary control plane; establishes communication with at least one external node; synchronizes with the at least one external node, the synchronizing comprising: comparing a checksum value of the at least one external node with a checksum value of the secondary control plane; and retransmitting data between the external node and the secondary control plane if the checksum values do not match.