R3303-HP HSR6800 Routers MPLS Configuration Guide

Ste

Command

Remarks

4. Set the LSP statistics reading

interval.

statistics interval interval-time

The default interval is 0 seconds.

The system does not read LSP

statistics.

Inspecting LSPs

In MPLS, the MPLS control plane is responsible for establishing LSPs. However, when an LSP fails to

forward data, the control plane cannot detect the LSP failure or cannot do so in time. This makes network

maintenance difficult. To find LSP failures in time and locate the failed node, the device provides the

following mechanisms:

• MPLS LSP ping

• MPLS LSP tracert

Configuring MPLS LSP ping

MPLS LSP ping is for testing the connectivity of an LSP. At the ingress, it adds the label for the FEC to be

inspected into an MPLS echo request, which then is forwarded along the LSP to the egress. The egress

processes the request packet and returns an MPLS echo reply to the ingress. An MPLS echo reply carrying

a success notification indicates that the LSP is normal, and an MPLS echo reply carrying an error code

indicates that the LSP has failed.

To test the connectivity of an LSP, perform the following task in any view:

Task Command

Use MPLS LSP ping to test MPLS LSP

connectivity.

ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m

wait-time | -r reply-mode | -s packet-size | -t time-out | -v ] * ipv4

dest-addr mask-length [ destination-ip-addr-header ]

Configuring MPLS LSP tracert

MPLS LSP tracert is for locating LSP errors. It consecutively sends the MPLS echo requests along the LSP to

be inspected, with the TTL increasing from 1 to a specific value. Then, each hop along the LSP returns an

MPLS echo reply to the ingress due to TTL timeout. So, the ingress can collect information about each hop

along the LSP, so as to locate the failed node. You can also use MPLS LSP tracert to collect important

information about each hop along the LSP, such as the label allocated.

To locate errors of an LSP, perform the following task in any view:

Task Command

Perform MPLS LSP tracert to locate

errors along an MPLS LSP.

tracert lsp [ -a source-ip | -exp exp-value | -h ttl-value | -r reply-mode |-t

time-out ] * ipv4 dest-addr mask-length [ destination-ip-addr-header ]