H3C Technologies H3C S12500 Series Switches - Manual (Page 114)

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Step Command Remarks
2. Enable OSPF and enter its
view.
ospf [ process-id | router-id
router-id | vpn-instance
vpn-instance-name ] *
N/A
3. Enable opaque LSA reception
and advertisement.
opaque-capability enable Not enabled by default.
4. Configure the neighbors for
which the router can serve as
a GR helper.
graceful-restart help { acl-number
| prefix prefix-list }
Optional.
The router can serve as a GR
helper for any OSPF neighbor by
default.
Configuring the non-IETF standard OSPF GR helper
Step Command Remarks
1. Enter system view. system-view N/A
2. Enable OSPF and enter its
view.
ospf [ process-id | router-id
router-id | vpn-instance
vpn-instance-name ] *
N/A
3. Enable the link-local signaling
capability.
enable link-local-signaling Disabled by default.
4. Enable the out-of-band
re-synchronization capability. enable
out-of-band-resynchronization
Disabled by default.
5. Configure the neighbors for
which the router can serve as
a GR helper.
graceful-restart help { acl-number
| prefix prefix-list }
Optional.
The router can serve as a GR
helper for any OSPF neighbor by
default.
Triggering OSPF Graceful Restart
Performing an active/standby switchover on a device, or performing the following configuration on an
OSPF switch, will trigger OSPF Graceful Restart.
To trigger OSPF Graceful Restart, perform the following command in user view:
Task Command
Trigger OSPF Graceful Restart. reset ospf [ process-id ] process graceful-restart
Configuring OSPF NSR
With OSPF NSR, the standby MPU backs up the link state information from the active MPU. Upon an
active/standby switchover, the link state information can recover automatically and the routes can be
regenerated without tearing down the adjacencies or impacting other services.
GR requires the cooperation of neighboring devices to recover routing information. NSR does not require
that, and is more popular in practice.