BigIron RX Series Configuration Guide 120353-1001810-01Configuring OSPFv3 48Assigning interfaces to an areaAfter you define OSPFv3 areas, you must assign router interfaces to the areas. All router interfacesmust be assigned to one of the defined areas on an OSPF router. When an interface is assigned toan area, all corresponding subnets on that interface are automatically included in the assignment.For example, to assign Ethernet interface 3/1 to area 192.5.0.0, enter the following commands.BigIron RX(config)# interface Ethernet 3/1BigIron RX(config-if-e100-3/1)# ipv6 ospf area 192.5.0.0Syntax: [no] ipv6 ospf area <number> | <ipv4-address>The <number> | <ipv4-address> parameter specifies the area number, which can be a number orin IPv4 address format. If you specify a number, the number can be from 0 – 2,147,483,647.To remove the interface from the specified area, use the no form of this command.Configuring virtual linksAll ABRs must have either a direct or indirect link to an OSPF backbone area (0.0.0.0 or 0). If anABR does not have a physical link to a backbone area, you can configure a virtual link from the ABRto another router within the same area that has a physical connection to the backbone area.The path for a virtual link is through an area shared by the neighbor ABR (router with a physicalbackbone connection) and the ABR requiring a logical connection to the backbone.Two parameters must be defined for all virtual links—transit area ID and neighbor router.• The transit area ID represents the shared area of the two ABRs and serves as the connectionpoint between the two routers. This number should match the area ID value.• When assigned from the router interface requiring a logical connection, the neighbor routerfield is the router ID (IPv4 address) of the router that is physically connected to the backbone.When assigned from the router interface with the physical connection, the neighbor router isthe router ID (IPv4) address of the router requiring a logical connection to the backbone.NOTEBy default, the Brocade router ID is the IPv4 address configured on the lowest numbered loopbackinterface. If the Brocade device does not have a loopback interface, the default router ID is thelowest numbered IPv4 address configured on the device.NOTEWhen you establish an area virtual link, you must configure it on both of the routers (both ends ofthe virtual link).For example, imagine that ABR1 in areas 1 and 2 is cut off from the backbone area (area 0). Toprovide backbone access to ABR1, you can add a virtual link between ABR1 and ABR2 in area 1using area 1 as a transit area. To configure the virtual link, you define the link on the router that isat each end of the link. No configuration for the virtual link is required on the routers in the transitarea.To define the virtual link on ABR1, enter the following command on ABR1.BigIron RX(config-ospf6-router)# area 1 virtual-link 209.157.22.1To define the virtual link on ABR2, enter the following command on ABR2.BigIron RX(config-ospf6-router)# area 1 virtual-link 10.0.0.1
