CISCO IOS in a Nutshell

Name

area virtual-link — router, OSPF

Synopsis

area area-idvirtual-link router-id [hello-interval seconds] 
    [retransmit-interval seconds] [transmit-delay seconds] 
    [dead-interval seconds] [authentication-key key] 
    [message-digest-key keyid md5 key]
no area area-id virtual-link router-id
            

Configures

An OSPF virtual link

Default

None

Description

This command establishes a virtual link that connects a broken OSPF backbone; in OSPF, the backbone must be contiguous. It is useful when a contiguous backbone is not possible. Virtual links can also be used to create an area that does not have a direct link to the backbone (area 0).

area-id

The ID of the area being crossed by the virtual link.

router-id

The ID of the router at the other end of the virtual link.

hello-interval seconds

Optional. The time in seconds between transmission of hello messages by the router over the virtual link. The default is 10 seconds. All routers participating in the same area must have the same hello interval.

retransmit-interval seconds

Optional. The time in seconds that a router waits before retransmitting a link-state announcement (LSA). The default is 5 seconds. When setting this value, you need to ensure that the time includes the entire round trip of the packet.

transmit-delay seconds

Optional. This is the estimated time in seconds that the interface will take to transmit the packet. An LSA’s age is decremented by this value before transmission. The default is 1 second.

dead-interval seconds

Optional. A router is ...