Reference Guide

NOTE: By default, OSPFv2 graceful restart is disabled.
To enable and configure OSPFv2 graceful restart, use the following commands.
1. Enable OSPFv2 graceful-restart globally and set the grace period.
CONFIG-ROUTEROSPF- id mode
graceful-restart grace-period seconds
The seconds range is from 40 and 3000.
This setting is the time that an OSPFv2 router’s neighbors advertises it as fully adjacent, regardless of the
synchronization state, during a graceful restart. OSPFv2 terminates this process when the grace period ends.
2. Enter the Router ID of the OSPFv2 helper router from which the router does not accept graceful restart assistance.
CONFIG-ROUTEROSPF- id mode
graceful-restart helper-reject router-id
– Planned-only — the OSPFv2 router supports graceful-restart for planned restarts only. A planned restart is
when you manually enter a fail-over command to force the primary RPM over to the secondary RPM.
During a planned restart, OSPF sends out a Grace LSA before the system switches over to the secondary
RPM. OSPF also is notified that a planned restart is happening.
– Unplanned-only — the OSPFv2 router supports graceful-restart for only unplanned restarts. During an
unplanned restart, OSPF sends out a Grace LSA after the secondary RPM comes online.
By default, OSPFv2 supports both planned and unplanned restarts. Selecting one or the other mode restricts
OSPFv2 to the single selected mode.
3. Configure the graceful restart role or roles that this OSPFv2 router performs.
CONFIG-ROUTEROSPF- id mode
graceful-restart role [helper-only | restart-only]
FTOS supports the following options:
– Helper-only: the OSPFv2 router supports graceful-restart only as a helper router.
– Restart-only: the OSPFv2 router supports graceful-restart only during unplanned restarts.
By default, OSPFv2 supports both restarting and helper roles. Selecting one or the other role restricts OSPFv2 to the
single selected role.
To disable OSPFv2 graceful-restart after you have enabled it, use the no graceful-restart grace-period
command in CONFIG-ROUTEROSPF- id mode. The command returns OSPF graceful-restart to its default state.
For more information about OSPF graceful restart, refer to the FTOS Command Line Reference Guide .
When you configure a graceful restart on an OSPFv2 router, the show run ospf command displays information
similar to the following.
Example of the show run ospf Command
FTOS#show run ospf
!
router ospf 1
graceful-restart grace-period 300
graceful-restart role helper-only
graceful-restart mode unplanned-only
graceful-restart helper-reject 10.1.1.1
graceful-restart helper-reject 20.1.1.1
network 10.0.2.0/24 area 0
FTOS#
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