Configuring Fast Reroute - Cisco NCS 5500 Series Configuration Manual

Implementing MPLS Traffic Engineering
• Stable router ID is required at either end of the link to ensure that the link is successful. If you do not
assign a router ID to the routers, the system defaults to the global router ID. Default router IDs are subject
to change, which can result in an unstable link.
Configuration Example
This example configures an MPLS-TE tunnel on the headend router with a destination IP address
192.168.92.125. The bandwidth for the tunnel, path-option, and forwarding parameters of the tunnel are also
configured. You can use static routing, autoroute announce or forwarding adjacency to steer traffic through
the tunnel.
RP/0/RP0/CPU0:router # configure
RP/0/RP0/CPU0:router(config)# interface tunnel-te 1
RP/0/RP0/CPU0:router(config-if)# destination 192.168.92.125
RP/0/RP0/CPU0:router(config-if)# ipv4 unnumbered Loopback0
RP/0/RP0/CPU0:router(config-if)# path-option 1 dynamic
RP/0/RP0/CPU0:router(config-if)# autoroute announce
RP/0/RP0/CPU0:router(config-if)# signalled-bandwidth 100
RP/0/RP0/CPU0:router(config)# commit
Verification
Verify the configuration of MPLS-TE tunnel using the following command.
RP/0/RP0/CPU0:router# show mpls traffic-engineering tunnels brief
Related Topics
• How MPLS-TE Works, on page 38
• Building MPLS-TE Topology , on page 39

Configuring Fast Reroute

Fast reroute (FRR) provides link protection to LSPs enabling the traffic carried by LSPs that encounter a
failed link to be rerouted around the failure. The reroute decision is controlled locally by the router connected
to the failed link. The headend router on the tunnel is notified of the link failure through IGP or through RSVP.
When it is notified of a link failure, the headend router attempts to establish a new LSP that bypasses the
failure. This provides a path to reestablish links that fail, providing protection to data transfer. The path of the
backup tunnel can be an IP explicit path, a dynamically calculated path, or a semi-dynamic path. For detailed
conceptual information on fast reroute, see
Before You Begin
The following prerequisites are required to create an MPLS-TE tunnel:
Signalling Summary:
LSP Tunnels Process:
RSVP Process:
Forwarding:
Periodic reoptimization:
Periodic FRR Promotion:
Auto-bw enabled tunnels:
TUNNEL NAME
tunnel-te1
Displayed 1 up, 0 down, 0 recovering, 0 recovered heads
MPLS Configuration Guide for Cisco NCS 5500 Series Routers, IOS XR Release 6.2.x
or forwarding adjacency
running
running
enabled
every 3600 seconds, next in 2538 seconds
every 300 seconds, next in 38 seconds
0 (disabled)
DESTINATION
192.168.92.125 up
MPLS-TE Features - Details, on page 51
Configuring MPLS-TE
STATUS STATE
up
41