Service Manual

● Specify how the OSPF interface cost is calculated based on the reference bandwidth method. The cost of an interface is
calculated as Reference Bandwidth/Interface speed.
ROUTER OSPFv3
auto-cost [reference-bandwidth ref-bw]
To return to the default bandwidth or to assign cost based on the interface type, use the no auto-cost [reference-
bandwidth ref-bw] command.
○ ref-bw: The range is from 1 to 4294967. The default is 100 megabits per second.
Enabling OSPFv3 Graceful Restart
Follow the procedure in this section to configure graceful restart for OSPFv3. 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.
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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 process-id command to enter OSPFv3 configuration
mode. Then configure a grace period using the graceful-restart grace-period command. The grace period is the time
that the OSPFv3 neighbors continue to advertise the restarting router as though it is fully adjacent. When you enable graceful
restart (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 using the ipv6 ospf graceful-restart helper-reject
command, you reconfigure OSPFv3 graceful restart to function in a restarting-only role. OSPFv3 does not participate in the
graceful restart of a neighbor.
NOTE: Enter the ipv6 ospf graceful-restart helper-reject command in Interface configuration mode.
NOTE: For graceful-restart configuration to work, you must configure grace-period. Use graceful-restart grace-
period command to configure grace-period.
● Enable OSPFv3 graceful restart globally by setting the grace period (in seconds).
CONF-IPV6-ROUTER-OSPF mode
graceful-restart grace-period seconds
The valid values are from 40 to 1800 seconds.
● Configure an OSPFv3 interface to not act on the Grace LSAs that it receives from a restarting OSPFv3 neighbor.
INTERFACE mode
ipv6 ospf graceful-restart helper-reject
● Specify the operating mode and type of events that trigger a graceful restart.
CONF-IPV6-ROUTER-OSPF mode
graceful-restart mode [planned-only | unplanned-only]
○ Planned-only: the OSPFv3 router supports graceful restart only for planned restarts. A planned restart is when you
manually enter a redundancy force-failover rpm command to force the primary RPM over to the secondary
RPM. During a planned restart, OSPFv3 sends out a Grace LSA before the system switches over to the secondary RPM.
OSPFv3 is notified that a planned restart is happening.
○ Unplanned-only: the OSPFv3 router supports graceful-restart only for unplanned restarts. During an unplanned
restart, OSPFv3 sends out a Grace LSA once the secondary RPM comes online.
The default is both planned and unplanned restarts trigger an OSPFv3 graceful restart. Selecting one or the other mode
restricts OSPFv3 to the single selected mode.
● Disable OSPFv3 graceful-restart.
CONF-IPV6-ROUTER-OSPF mode
no graceful-restart grace-period
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Open Shortest Path First (OSPFv2 and OSPFv3)