H3C Technologies H3C SR8800 - Manual (Page 117)

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OSPF calculates the shortest path based on the new network topology, and forwards packets over the
path after routing convergence.
You can either configure OSPF FRR to calculate a backup next hop automatically, or to designate a
backup next hop by using a routing policy.
Configuration prerequisites
Before you configure OSPF FRR, complete the following tasks:
• Configure network layer addresses for interfaces.
• Enable OSPF.
Configuring OSPF FRR to automatically calculate a backup next hop
To configure automatic OSPF FRR:
Step Command Remarks
1. Enter system view. system-view N/A
2. Configure the source address
of echo packets.
bfd echo-source-ip ip-address Not configured by default.
3. Enter OSPF view.
ospf [ process-id | router-id
router-id | vpn-instance
vpn-instance-name ] *
N/A
4. Enable OSPF FRR to
automatically calculate a
backup next hop.
fast-reroute auto [ abr-only ]
Not configured by default.
If abr-only is specified, the route to
the ABR is selected as the backup
path.
Configuring OSPF FRR to designate a backup next hop with a routing policy
Before configuring this task, use the apply fast-reroute backup-interface command to specify a backup
next hop in the routing policy to be referenced. For more information about the apply fast-reroute
backup-interface command and routing policy configuration, see the chapter “Configuring routing
policies.”
To configure OSPF FRR:
Step Command Remarks
1. Enter system view. system-view N/A
2. Configure the source address
of echo packets.
bfd echo-source-ip ip-address Not configured by default
3. Enter OSPF view.
ospf [ process-id | router-id
router-id | vpn-instance
vpn-instance-name ] *
N/A
4. Enable OSPF FRR to
designate a backup next hop
by using a routing policy.
fast-reroute route-policy
route-policy-name
Not configured by default
Configuring OSPF Graceful Restart
OSPF GR involves: