BigIron RX Series Configuration Guide 68753-1001986-01Configuring OSPF 25Block flooding of outbound LSAs on specific OSPFinterfacesBy default, the device floods all outbound LSAs on all the OSPF interfaces within an area. You canconfigure a filter to block outbound LSAs on an OSPF interface. This feature is particularly usefulwhen you want to block LSAs from some, but not all, of the interfaces attached to the area.After you apply filters to block the outbound LSAs, the filtering occurs during the databasesynchronization and flooding.If you remove the filters, the blocked LSAs are automatically re-flooded. You do not need to resetOSPF to re-flood the LSAs.NOTEYou cannot block LSAs on virtual links.To apply a filter to an OSPF interface to block flooding of outbound LSAs on the interface, enter thefollowing command at the Interface configuration level for that interface.BigIron RX(config-if-e10000-1/1)# ip ospf database-filter all outThe command in this example blocks all outbound LSAs on the OSPF interface configured on port1/1.Syntax: [no] ip ospf database-filter all outTo remove the filter, enter a command such as the following.BigIron RX(config-if-e10000-1/1)# no ip ospf database-filter all outAssign virtual linksAll ABRs (area border routers) must have either a direct or indirect link to the OSPF backbone area(0.0.0.0 or 0). If an ABR does not have a physical link to the area backbone, the ABR can configurea virtual link to another router within the same area, which has a physical connection to the areabackbone.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 fields 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.• The neighbor router field is the router ID (IP address) of the router that is physically connectedto the backbone, when assigned from the router interface requiring a logical connection. Whenassigning the parameters from the router with the physical connection, the router ID is the IPaddress of the router requiring a logical connection to the backbone.NOTEBy default, the Brocade router ID is the IP address configured on the lowest numbered loopbackinterface. If the device does not have a loopback interface, the default router ID is the lowestnumbered IP address configured on the device. For more information or to change the router ID,refer to “Changing the router ID” on page 180.
