Configuring Mpls Oam; Overview; Mpls Ping; Mpls Traceroute - HP MSR2000 Configuration Manual

Configuring MPLS OAM

Overview

MPLS Operation, Administration, and Maintenance (OAM) provides fault management tools for the
following:
MPLS data plane connectivity verification.
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Data plane and control plane consistency verification.
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Fault locating.
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These fault management tools include the following types:
On-demand tools—Tools that need to be triggered manually, such as MPLS ping and MPLS
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traceroute.
Proactive tools—Tools that are triggered by the system automatically, such as periodic MPLS
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traceroute, and MPLS BFD.
You can use these tools to detect and locate faults of LSPs, MPLS TE tunnels, and MPLS PWs.

MPLS ping

MPLS ping tests the connectivity of an LSP tunnel, an MPLS TE tunnel, or a PW. At the ingress node, MPLS
ping adds the label associated with a tunnel into an MPLS echo request and sends it to the egress node
over the tunnel. The egress node processes the request and returns an MPLS echo reply to the ingress
node. An MPLS echo reply with a success notification indicates that the tunnel is available for data
forwarding, and an MPLS echo reply with an error code indicates that the tunnel has failed.

MPLS traceroute

MPLS traceroute displays the path that an MPLS LSP tunnel or an MPLS TE tunnel travels from the ingress
node to the egress node to locate errors on the tunnel. MPLS traceroute consecutively sends MPLS echo
requests along the LSP tunnel, with the TTL increasing from 1 to a specific value. Each hop along the
tunnel returns an MPLS echo reply to the ingress due to TTL timeout so the ingress can collect information
about each hop along the tunnel. This information allows you to locate the failed node or access
information for each hop, for example, the label allocated by each downstream hop.

Periodic MPLS traceroute

The periodic MPLS traceroute function automatically traces an LSP tunnel at a specific interval. It locates
errors on the LSP tunnel, verifies the consistency of the data plane and control plane, and records the
detected errors in system logs. You can check the logs to monitor LSP connectivity.
If both BFD and periodic MPLS traceroute are configured for an LSP, and the periodic traceroute function
detects a data plane and control plane inconsistency, the device does the following:
1. Deletes the BFD session for the LSP.
2. Reestablishes the BFD session based on the control plane.
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