Patent ID: 7610405

Claim:
A computer-implemented method for reprogramming an active packet switching router without interfering with packet flow, said method comprising: receiving a software upgrade message at a currently active packet switching device (A); halting receipt of new packets at said packet switching device (A) upon receipt of said software upgrade message; transferring protocol state information, including routing tables, negotiated state information, authorization status and learned routing state information, from said packet switching device (A) to a currently inactive packet switching device (B); reprogramming said packet switching device (B); sending a message requesting activation from said packet switching device (A) to said packet switching device (B); de-activating said packet switching device (A) and activating said reprogrammed packet switching device (B) to handle packet flow previously handled by said packet switching device (A), including beginning receipt of new packets at said packet switching device (B); reprogramming said packet switching device (A), including retrieving new packet processing software from a remote location; and thereafter de-activating said packet switching device (B) and re-activating said packet switching device (A).