mpls te fast-reroute
Use mpls te fast-reroute to enable fast reroute (FRR).
Use undo mpls te fast-reroute to disable FRR.
Syntax
mpls te fast-reroute [ bandwidth ]
undo mpls te fast-reroute
Default
FRR is disabled.
Views
Tunnel interface view
Predefined user roles
network-admin
Parameters
bandwidth: Provides bandwidth protection for the primary CRLSP. If you do not specify this keyword, bandwidth protection is not provided for the primary CRLSP.
Usage guidelines
FRR provides a quick link or node protection on a CRLSP. FRR traffic switching can happen in as fast as 50 milliseconds, minimizing data loss.
After FRR is enabled for an MPLS TE tunnel, once a link or node fails on the primary CRLSP, the following events occur:
FRR reroutes the traffic to a bypass tunnel.
The ingress node attempts to set up a new CRLSP.
After the new CRLSP is set up successfully, traffic is forwarded on the new CRLSP.
When a primary CRLSP does not need bandwidth protection, it prefers to use a bypass tunnel that does not provide bandwidth protection. No bandwidth guarantee is required after FRR.
When a primary CRLSP needs bandwidth protection, it prefers to use the bypass tunnel that can protect bandwidth as much as possible to provide bandwidth guarantee after FRR.
Regardless of whether a primary CRLSP requires bandwidth protection, the following will occur when the primary CRLSP is bound to a bypass tunnel that provides bandwidth protection:
The bypass tunnel will reserve the protected bandwidth for the primary CRLSP.
The RRO message of the PLR will carry the bandwidth protection flag.
After FRR is enabled for a tunnel, the label recording feature is automatically enabled for the tunnel, regardless of whether the mpls te record-route label command is configured.
If both the mpls te fast-reroute and mpls te bidirectional commands are configured, only the mpls te bidirectional command takes effect.
Examples
# Enable FRR for Tunnel 0.
<Sysname> system-view [Sysname] interface tunnel 0 mode mpls-te [Sysname-Tunnel0] mpls te fast-reroute
Related commands
display mpls te tunnel-interface
mpls te backup bandwidth