Service Manual

Version Description
9.2(0.0) Introduced on the MXL 10/40GbE Switch IO Module.
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.
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
Version Description
9.9(0.0) Introduced on the FN IOM.
9.2(0.0) Introduced on the MXL 10/40GbE Switch IO Module.
Usage Information
OSPFv3 graceful restart supports planned-only and/or unplanned-only restarts. The default is support for both
planned and unplanned restarts.
• A planned restart occurs when you enter the redundancy force-failover rpm command to force the
primary RPM to switch to the backup RPM. During a planned restart, OSPF sends out a Type-11 Grace LSA
before the system switches over to the backup RPM.
• An unplanned restart occurs when an unplanned event causes the active RPM to switch to the backup RPM,
such as when an active process crashes, the active RPM is removed, or a power failure happens. During an
unplanned restart, OSPF sends out a Grace LSA when the backup RPM comes online.
By default, both planned and unplanned restarts trigger an OSPFv3 graceful restart. Selecting one or the other
mode restricts OSPFv3 to the single selected mode.
Open Shortest Path First (OSPFv2 and OSPFv3) 917