Mpls Lsp Traceroute - Cisco NCS 5500 Series Configuration Manual

Implementing MPLS OAM
Receive Counts:
Unknown Pkt Types:
IP header error:
UDP header error:
Dropped (Q full):
Error, no memory:
Transmit Counts:

MPLS LSP Traceroute

The MPLS LSP Traceroute feature is used to isolate the failure point of an LSP. It is used for hop-by-hop
fault localization and path tracing. The MPLS LSP Traceroute feature relies on the expiration of the Time to
Live (TTL) value of the packet that carries the echo request. When the MPLS echo request message hits a
transit node, it checks the TTL value and if it is expired, the packet is passed to the control plane, else the
message is forwarded. If the echo message is passed to the control plane, a reply message is generated based
on the contents of the request message.
The following figure shows an MPLS LSP traceroute example with an LSP from LSR1 to LSR4.
Figure 13: MPLS LSP Traceroute
Configuration Examples
This example shows how to use the traceroute command to trace to a destination with Forwarding Equivalence
Class (FEC) type specified as generic.
RP/0/RP0/CPU0:router# traceroute mpls ipv4 3.3.3.3/32 fec-type generic
Mon Nov 30 17:48:45.585 UTC
Tracing MPLS Label Switched Path to 3.3.3.3/32, timeout is 2 seconds
Pkt
---------------
Good Requests:
Good Replies:
Runts:
General error:
Error, no IF:
Good:
Dropped:
MPLS Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.2.x
Bytes
---------------
0 0
10 760
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
10 960
0 0
MPLS LSP Traceroute
61