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the same for all routers attached to an autonomous system.
(Range: 1-65535 seconds; Default: 4 x hello interval, or 40 seconds)
• hello-interval seconds - Specifies the transmit delay between sending
hello packets. Setting the hello interval to a smaller value can reduce the
delay in detecting topological changes, but will increase the routing traffic.
This value must be the same for all routers attached to an autonomous
system. (Range: 1-65535 seconds; Default: 10 seconds)
• retransmit-interval seconds - Specifies the interval at which the ABR
retransmits link-state advertisements (LSA) over the virtual link. The
retransmit interval should be set to a conservative value that provides an
adequate flow of routing information, but does not produce unnecessary
protocol traffic. However, note that this value should be larger for virtual
links. (Range: 1-3600 seconds; Default: 5 seconds)
• transmit-delay seconds - Estimates the time required to send a link-state
update packet over the virtual link, considering the transmission and
propagation delays. LSAs have their age incremented by this amount
before transmission. This value must be the same for all routers attached
to an autonomous system. (Range: 1-3600 seconds; Default: 1 seconds)
Command Mode
Router Configuration
Default Setting
area-id: None
router-id: None
hello-interval: 10 seconds
retransmit-interval: 5 seconds
transmit-delay: 1 second
dead-interval: 40 seconds
authentication-key: None
message-digest-key: None
Command Usage
• All areas must be connected to a backbone area (0.0.0.0) to maintain routing
connectivity throughout the autonomous system. If it not possible to physically
connect an area to the backbone, a virtual link can be used. A virtual link can
provide a logical path to the backbone for an isolated area, or can be
configured as a backup connection that can take over if the normal connection
to the backbone fails. You can specify up to 32 virtual links on this router.
• A virtual link can be configured between any two backbone routers that have
an interface to a common non-backbone area. The two routers joined by a
virtual link are treated as if they were connected by an unnumbered
point-to-point network.
• Any area disconnected from the backbone must include the transit area ID
and the router ID for a virtual link neighbor that is adjacent to the backbone.
• This router supports up 64 virtual links.
Open Shortest Path First (OSPF)
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