traffic recovery time. Meanwhile, IS-IS calculates the shortest path based on the new network topology,
and forwards packets over the path after network convergence.
You can either enable IS-IS FRR to calculate a backup next hop automatically, or to designate a backup
next hop with a routing policy for routes matching specific criteria.
Configuration prerequisites
Before you configure IS-IS FRR, complete the following tasks:
Configure IP addresses for interfaces, and make sure that all neighboring nodes can reach each
•
other at the network layer.
Enable IS-IS.
•
Configuration guidelines
Do not use FRR and BFD at the same time. Otherwise, FRR may fail to take effect.
•
The automatic backup next hop calculation of FRR and that of TE are mutually exclusive.
•
Configuring IS-IS FRR to automatically calculate a backup next hop
Step
1.
Enter system view.
2.
Configure the source address
of echo packets.
3.
Enter IS-IS view.
Enable IS-IS FRR to
4.
automatically calculate a
backup next hop.
Configuring IS-IS FRR to designate a backup next hop with a routing policy
You can use the apply fast-reroute backup-interface command to specify a backup next hop in a routing
policy for routes matching specific criteria. For more information about the apply fast-reroute
backup-interface command and routing policy configurations, see the "Configuring routing policies."
To configure IS-IS FRR:
Step
1.
Enter system view.
2.
Configure the source address
of echo packets.
3.
Enter IS-IS view.
4.
Enable IS-IS FRR to designate
a backup next hop by using a
routing policy.
Command
system-view
bfd echo-source-ip ip-address
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
fast-reroute auto
Command
system-view
bfd echo-source-ip ip-address
isis [ process-id ] [ vpn-instance
vpn-instance-name ]
fast-reroute route-policy
route-policy-name
158
Remarks
N/A
Not configured by default
N/A
Not configured by default
Remarks
N/A
Not configured by default.
N/A
Not configured by default.