A Profile
Means a virtual link between two the ABR, through a non-backbone area (transfer area --Transit Area), connected to a logical channel established, it is understood that there is a point to point connection between two ABR. "Logical channel" means running OSPF router between two ABR only play a role of forwarding packets (since the destination address of these packets are not routers, so these packets are transparent to them, but as common IP packets to forwarding), routing information is transmitted directly between the two ABR. Herein refers to the routing information generated by the ABR type3 LSA, the router synchronization mode in the area has not changed.
Virtual Connection (Virtual-link): Because of the complex topology of the network, may not meet the requirements of each zone and the backbone area must be directly connected, in order to solve this problem, OSPF proposed the concept of a virtual link.
Virtual connection is provided between the two routers, a router has two ports with the same non-contiguous backbone area. Virtual link is considered to belong to the region of the backbone, in the OSPF routing protocol opinion, a virtual link two routers are connected together in a point to point link. In the OSPF routing protocol, routing information is a virtual connection route art to look at.
Two commands
Router (config-Router) #area-Area-Virtual Link ID Router-ID
. 1, in the configuration mode selected under the OSPF routing,
2, Area-ID: No. region
3, Router-id: routing to the target virtual link ID
4 , you need to configure both ABR.
Three build process
GNS3 built in, as shown in FIG topology.
Press the topology shown in FIG. 1, the configuration R4
R1 Configuration 2
R2 Configuration 3
R3 Configuration 4
5 pc machine configuration two sets of
Building virtual link 6
7 Interoperability Testing
