the same for all routers attached to an autonom ous sy stem.
(Range: 1-65535 seconds; Default: 4 x hello interval, or 40 seco nds)
• hello-interval seconds - Specifies the transmi t delay betwee n sending
hello packets. Setting the hello interval to a smaller value can re duce the
delay in detecting topological changes, but will increase the routing traffic.
This value must be the same for all routers attached to an auto nomous
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 conservati ve value that p rovides a n
adequate flow of routing information, but does not produce unnecessa ry
protocol traffic. However, note that this value should b e larger for virtu al
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 transm ission a nd
propagation delays. LSAs have their age incremented by this amount
before transmission. This value must be the same for all route rs 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 u sed. A v irtual l ink can
provide a logical path to the backbone for an isolat ed area, or ca n be
configured as a backup connection that can take over if the normal connection
to the backbone fails. You can specify up to 32 virt ual links on th is router.
• A virtual link can be configured between any two back bone rout ers t hat hav e
an interface to a common non-backbone area. The t wo router s joined by a
virtual link are treated as if they were connected by an unnum bered
point-to-point network.
• Any area disconnected from the backbone must include the transit area ID
and the router ID for a virtual link neighb or that is ad jacent to the b ackbone.
• This router support s up 64 vir tual links.
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Open Shortest Path First (OSPF)
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