This KB is to document the limitation of PTX-EVO router with mpls ldp/ping traceroute.

MPLS PING and TRACE-ROUTE destined to PTX doesn't work even though LSP is UP.

However, if neighbour device is NOT PTX-EVO, then ping/trace from PTX towards neighbour can be successful.

-> Ping from the neighbour:

r1> ping mpls ldp 192.168.0.20   

.....

--- lsping statistics ---

5 packets transmitted, 0 packets received, 100% packet loss

-> Trace-route from the neighbour:

r1> traceroute mpls segment-routing isis 192.168.0.20   

error: timeout communicating with mpls-traceroute daemon

-> Ping to the neighbour:

r1> ping mpls ldp 192.168.0.10

!!!!!

--- lsping statistics ---

5 packets transmitted, 5 packets received, 0% packet loss

This is a platform limitation and working as per design.

Need to apply below configuration to make MPLS ping/traceoute work on this platform.

set interfaces lo0 unit 0 family inet address 127.0.0.1/32