H3C Technologies H3C SR8800 - Manual (Page 93)

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To locate errors of an MPLS TE tunnel:
Task Command
Use MPLS LSP tracert to locate
errors of an MPLS TE tunnel. tracert lsp [ -a source-ip | -exp exp-value | -h ttl-value | -r reply-mode |-t
time-out ] * te interface-type interface-number
Configuring BFD for an MPLS TE tunnel
You can configure BFD for an MPLS TE tunnel to implement fast detection of the connectivity of the tunnel.
After you configure BFD for an MPLS TE tunnel, a BFD session will be established between the ingress
and egress of the tunnel, and the ingress will add the label for the tunnel into a BFD control packet,
forward the BFD control packet along the tunnel, and determine the status of the tunnel according to the
BFD control packet received from the egress. Upon detecting an MPLS TE tunnel failure, BFD triggers
protection switching to switch traffic to another tunnel.
A BFD session for MPLS TE tunnel detection can be static or dynamic.
• Static: If you specify the local and remote discriminator values by using the discriminator keyword
when configuring the mpls te bfd enable command, the BFD session will be established with the
specified discriminator values. Such a BFD session can detect the connectivity of a pair of MPLS TE
tunnels in opposite directions (one from local to remote, and the other from remote to local) between
two routers.
• Dynamic: If you do not specify the local and remote discriminator values when configuring the mpls
te bfd enable command, the MPLS LSP ping will be run automatically to negotiate the discriminator
values and then the BFD session will be established based on the negotiated discriminator values.
Such a BFD session can detect the connectivity of a unidirectional (from the local router to the
remote router) MPLS TE tunnel between two routers.
After you enable BFD and configure the mpls te failure-action teardown command for an MPLS TE tunnel,
once an RSVP-TE tunnel failure occurs, BFD can detect the failure, and if RSVP does not re-establish the
tunnel within a specific period of time, MPLS TE will remove the failed RSVP-TE tunnel and then
re-establish it.
To configure BFD for an MPLS TE tunnel:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable LSP verification and
enter MPLS LSPV view.
mpls lspv
By default, LSP verification is
disabled.
3. Return to system view. quit N/A
4. Enter the tunnel interface view
of an MPLS TE tunnel.
interface tunnel tunnel-number N/A
5. Configure BFD to check the
connectivity of the MPLS TE
tunnel.
mpls te bfd enable [ discriminator
local local-id remote remote-id ]
By default, BFD is not configured to
check connectivity of MPLS TE
tunnels.
6. Configure MPLS TE to tear
down a failed RSVP TE tunnel
and reestablish it.
mpls te failure-action teardown
Optional.
Not configured by default.