Routing Commands
323
ProSafe Managed Switch
thereby avoiding announcement of a topology change and the potential for flooding of LSAs
and shortest-path-first (SPF) runs, which determine OSPF routes. Helpful neighbors continue
to forward packets through the restarting router. The restarting router relearns the network
topology from its helpful neighbors.
Graceful restart can be enabled for planned or unplanned restarts, or both. A planned restart
is initiated by the operator through the management command initiate failover. The operator
may initiate a failover to take the management unit out of service (for example, to address a
partial hardware failure), to correct faulty system behavior that cannot be corrected through
less severe management actions, or other reasons. An unplanned restart is an unexpected
failover, caused by a fatal hardware failure of the management unit or a software hang or
crash on the management unit.
nsf
Use this command to enable the OSPF graceful restart functionality on an interface. To
disable graceful restart, use the no form of the command.

no nsf

Use this command to disable graceful restart for all restarts.
nsf restart-interval
Use this command to configure the number of seconds that the restarting router asks its
neighbors to wait before exiting helper mode. This is called the “grace period.” The restarting
router includes the grace period in its grace LSAs. For planned restarts (using the initiate
failover command), the grace LSAs are sent prior to restarting the management unit,
whereas for unplanned restarts, they are sent after reboot begins. The grace period must be
Default Disabled
Format nsf [ietf] [planned-only]
Modes OSPF Router Configuration
Parameter Description
ietf This keyword is accepted but not required.
planned-only This optional keyword indicates that OSPF should perform only a graceful restart when
the restart is planned (that is, when the restart is a result of the initiate failover
command).
Format no nsf
Modes OSPF Router Configuration