D-Link DGS-6600-48T Product Manual - Page 62

DGS-6604 m Examples area virtual-link (IPv6) In OSPF, all non-backbone areas must be connected to a backbone area. If the connection to the backbone is lost, the virtual link repairs the connection. Virtual links can be configured between any two backbone-routers that have an interface to a common non-backbone area. The protocol treats these two routers joined by a virtual link as if they were connected by an un-numbered point-topoint 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 incremented by this amount. Set the transmit-delay to be greater than zero. Also, take into account the transmission and propagation delays for the interface. To configure a virtual link in OSPF for IPv6, a router ID must be used instead of an address. In the IPv6 version of OSPF, the virtual link takes the router ID rather than the IPv6 prefix of the remote router. The following example establishes a virtual link with default values for all optional parameters. Switch > enable Switch # configure terminal Switch (config) # router ipv6 ospf Switch (config-router)# area 1 virtual-link 192.168.255.1 CLI Reference Guide 52