Reference Guide

Parameters
seconds Time duration, in seconds, that specifies the duration of the restart
process before OSPFv3 terminates the process. The range is from 40
to 1800 seconds.
Defaults OSPFv3 graceful restart is disabled and functions in a helper-only role.
Command Modes ROUTER OSPFv3
Command History
This guide is platform-specific. For command information about other platforms, refer to the
relevant FTOS Command Line Reference Guide .
The following is a list of the FTOS version history for this command.
Version 9.1.(0.0) Introduced on the S4810 and Z9000.
Version 8.4.2.2 Introduced on the E-Series TeraScale.
Version 8.3.19.0 Introduced on the S4820T.
Usage
Information
By default, OSPFv3 graceful restart is disabled and functions only in a helper role to help
restarting neighbor routers in their graceful restarts when it receives a Grace LSA.
To enable OSPFv3 graceful restart, enter the ipv6 router ospf command to enter OSPFv3
configuration mode and then configure a grace period using the graceful-restart grace-period
command. The grace period is the length of time that OSPFv3 neighbors continue to advertise
the restarting router as though it is fully adjacent. When graceful restart is enabled (restarting
role), an OSPFv3 restarting expects its OSPFv3 neighbors to help when it restarts by not
advertising the broken link.
When you enable the helper-reject role on an interface with the ipv6 ospf graceful-restart
helper-reject command, you reconfigure OSPFv3 graceful restart to function in a “restarting-
only” role. In a “restarting-only” role, OSPFv3 does not participate in the graceful restart of a
neighbor.
graceful-restart mode
Specify the type of events that trigger an OSPFv3 graceful restart.
S4820T
Syntax
graceful-restart mode {planned-only | unplanned-only}
To disable graceful restart mode, enter no graceful-restart mode.
Parameters
planned-only (OPTIONAL) Enter the keywords planned-only to indicate
graceful restart is supported in a planned restart condition only.
unplanned-only (OPTIONAL) Enter the keywords unplanned-only to indicate
graceful restart is supported in an unplanned restart condition only.
Defaults OSPFv3 graceful restart supports both planned and unplanned failures.
Command Modes ROUTER OSPFv3
Command History
This guide is platform-specific. For command information about other platforms, refer to the
relevant FTOS Command Line Reference Guide .
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