Operating MPLS label switched paths and MPLS pseudowire in loopback mode

摘要

In one embodiment, a circuit that extends between a head-end label switching router (LSR) and a tail-end LSR and traverses one or more intermediate LSRs is locked to data plane traffic. The head-end LSR transmits a packet along the circuit that includes a particular time-to-live (TTL) value configured to expire at a particular intermediate LSR at which loopback is to occur. The circuit is used in a loopback mode. The head-end LSR transmits along the circuit a packet that includes a cease loopback request. The circuit ceases to be used in the loopback mode. The circuit is unlocked to permit the circuit to pass data plane traffic.