Ospf Graceful Restart Commands; Show Ip Ospf Virtual-Link Brief - NETGEAR ProSafe GSM7224P User Manual

show ip ospf virtual-link brief

This command displays the OSPF Virtual Interface information for all areas in the system.
Format
show ip ospf virtual-link brief
Modes
• Privileged EXEC
• User EXEC
Term Definition
Area ID
The area id of the requested OSPF area.
Neighbor
The neighbor interface of the OSPF virtual interface.
Hello Interval
The configured hello interval for the OSPF virtual interface.
Dead Interval
The configured dead interval for the OSPF virtual interface.
Retransmit
The configured retransmit interval for the OSPF virtual interface.
Interval
Transit Delay
The configured transit delay for the OSPF virtual interface.

OSPF Graceful Restart Commands

The OSPF protocol can be configured to participate in the checkpointing service, so that
these protocols can execute a graceful restart when the management unit fails. In a graceful
restart, the hardware to continues forwarding IPv4 packets using OSPF routes, while a
backup switch takes over management unit responsibility.
Graceful restart uses the concept of "helpful neighbors." A fully adjacent router enters helper
mode when it receives a link state announcement (LSA) from the restarting management unit
indicating its intention of performing a graceful restart. In helper mode, a switch continues to
advertise to the rest of the network that they have full adjacencies with the restarting router,
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.
ProSafe Managed Switch
Routing Commands
305