Netgear M4100-50G Manuel D’Utilisation

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 
might 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. 

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 

Disabled

nsf [ietf] [planned-only] 

OSPF Router Configuration

This keyword is accepted but not required.

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).

no nsf 

OSPF Router Configuration