Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 326)

The point-to-point parameter specifies that the OSPF interface will support point-to-point networking.
This is the default setting for tunnel interfaces.
The broadcast parameter specifies that the OSPF interface will support broadcast networking. This is
the default setting for Ethernet and VE interfaces.
The no form of the command disables the command configuration.
Configuring virtual links
All ABRs must have either a direct or indirect link to an OSPF backbone area (0.0.0.0 or 0). If an ABR
does not have a physical link to a backbone area, you can configure a virtual link from the ABR to
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 physical
backbone 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 connection point
between the two routers. This number should match the area ID value.
• The neighbor router is the router ID (IPv4 address) of the router that is physically connected to the
backbone when assigned from the router interface requiring a logical connection. The neighbor
router is the router ID (IPv4 address) of the router requiring a logical connection to the backbone
when assigned from the router interface with the physical connection.
NOTE
By default, the router ID is the IPv4 address configured on the lowest-numbered loopback interface. If
the device does not have a loopback interface, the default router ID is the lowest-numbered IPv4
address configured on the device.
When you establish an area virtual link, you must configure it on both ends of the virtual link. For
example, imagine that ABR1 in areas 1 and 2 is cut off from the backbone area (area 0). To provide
backbone access to ABR1, you can add a virtual link between ABR1 and ABR2 in area 1 using area 1
as a transit area. To configure the virtual link, you define the link on the router that is at each end of
the link. No configuration for the virtual link is required on the routers in the transit area.
To define the virtual link on ABR1, enter the following command on ABR1.
device(config-ospf6-router)# area 1 virtual-link 10.157.22.1
To define the virtual link on ABR2, enter the following command on ABR2.
device(config-ospf6-router)# area 1 virtual-link 10.0.0.1
Syntax: [no] area {number | ipv4-address} virtual-link router-id
The number and ipv4-address parameters specify the transit area ID, area number, which can be a
number, or in IPv4 address format. If you specify a number, the number can be from 0 through
2,147,483,647.
The router-id parameter specifies the router ID of the OSPF router at the remote end of the virtual link.
To display the router ID on a router, enter the show ip command.
Modifying virtual link parameters
You can modify the following virtual link parameters:
Configuring virtual links
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