D-Link DGS-6600 Series, Manual

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DGS-6604 m area virtual-link
CLI Reference Guide
48
Default
• AREA-ID : None
• ROUTER-ID: None
• authentication : null
• hello-interva l:10 seconds
• dead-interva l: 40 seconds
• transmit-delay : 1 second
• retransmit-interval : 5 seconds
• authentication-key: None
• message-digest-key : None
Command Mode
Router configuration
Usage Guideline
In OSPF, all non-backbone areas must be connected to a backbone area. If the
connection to the backbone is broken, the virtual link is used to re-establish the
connection. Virtual links between any two backbone-routers that have an
interface to a common non-backbone area can be configured. The protocol treats
these two routers joined by a virtual link as if they were connected by an un-
numbered point-to-point network. To configure a virtual link, include both the
transit
AREA ID and the corresponding virtual link neighbor's ROUTER-ID in the
virtual link neighbor.
Configure the hello-interval to be the same for all routers attached to a common
network. A short hello interval results in the router detecting topological changes
faster but also an increase in the routing traffic.
As with the hello interval, the value of dead-interval must be the same for all
routers and access servers attached to a common network.
The retransmit-interval is the expected round-trip delay between any two
routers in a network. Set the value to be greater than the expected round-trip
delay to avoid needless retransmissions.
The transmit-delay is the time taken to transmit a link state update packet on the
interface. Before transmission, the link state advertisements in the update
packet, are incremental by this amount. Set the
transmit-delay to be greater
than zero. Also, take into account the transmission and propagation delays for
the interface.
Before using the area virtual-link authentication command, configure a
password for virtual link using the area virtual-link authentication-key
command. If the area virtual-link authentication message-digest command is
used, configure the message-digest key for the virtual link using area virtual-link
message-digest-key command.