MPLS and RSVP
7210 SAS M, T, X, R6, Mxp MPLS Configuration Guide Page 137
If an LSP is configured with fast-reroute frr-method specified but does not enable CSPF, then neither
global revertive nor local revertive will be available for the LSP to recover.
Default no cspf
Parameters use-te-metric — Specifies to use the use of the TE metric for the purpose of the LSP path computation
by CSPF.
exclude
Syntax [no] exclude group-name [group-name...(up to 5 max)]
Context config>router>mpls>lsp
Description This command specifies the admin groups to be excluded when an LSP is set up in the primary or
secondary contexts. Each single operation of the exclude command allows a maximum of 5 groups to
be specified at a time. However, a maximum of 32 groups can be specified per LSP through multiple
operations. The admin groups are defined in the config>router>mpls>admin-group context.
Use the no form of the command to remove the exclude command.
Default no exclude
Parameters group-name — Specify the existing group-name to be excluded when an LSP is set up.
fast-reroute
Syntax fast-reroute frr-method
no fast-reroute
Context config>router>mpls>lsp
Description This command creates a pre-computed detour LSP from each node in the path of the LSP. In case of
failure of a link or LSP between two nodes, traffic is immediately rerouted on the pre-computed
detour LSP, thus avoiding packet-loss.
When fast-reroute is enabled, each node along the path of the LSP tries to establish a detour LSP as
follows:
• Each upstream node sets up a detour LSP that avoids only the immediate downstream node, and
merges back on to the actual path of the LSP as soon as possible.
If it is not possible to set up a detour LSP that avoids the immediate downstream node, a detour
can be set up to the downstream node on a different interface.
• The detour LSP may take one or more hops (see hop-limit) before merging back on to the main
LSP path.
• When the upstream node detects a downstream link or node failure, the ingress router switches
traffic to a standby path if one was set up for the LSP.
Fast reroute is available only for the primary path. No configuration is required on the transit hops of
the LSP. The ingress router will signal all intermediate routers using RSVP to set up their detours. TE
must be enabled for fast-reroute to work.
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