LSP traceroute sends a packet to each transit LSR along a communications path until the far-end router is reached. The path is traced one LSR at a time, where each LSR that receives a traceroute packet replies to the initiating 7705 SAR with a packet that identifies itself. When the final LSR is identified, the initiating LSR has a list of all LSRs on the path. Like IP traceroute, LSP traceroute is a hop-by-hop operation (that is, LSR by LSR).
Use LSP traceroute to determine the exact litigation of LSP failures.