Brocade Virtual ADX Switch and Router Guide (Supporting ADX v03.1.00) - Manual (Page 172)

158 Brocade Virtual ADX Switch and Router Guide
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Enabling OSPFv3
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The stub metric parameter specifies an additional cost for using a route to or from this area and
can be from 1 through 16,777,215. There is no default. Normal areas do not use the cost
parameter.
The no-summary parameter applies only to stub areas and disables summary LSAs from being sent
into the area.
Assigning interfaces to an area
After you define OSPFv3 areas, you must assign router interfaces to the areas. All router interfaces
must be assigned to one of the defined areas on an OSPF router. When an interface is assigned to
an area, all corresponding subnets on that interface are automatically included in the assignment.
For example, to assign Ethernet interface 1 to area 192.5.0.0, enter the following commands:
Virtual ADX(config)#interface ethernet 1
Virtual ADX(config-if-e100-1)#ipv6 ospf area 192.5.0.0
Syntax: [no] ipv6 ospf area number | ipv4-address
The number | ipv4-address parameter specifies the 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.
To remove the interface from the specified area, use the no form of this command.
Changing the reference bandwidth for the
cost on OSPFv3 interfaces
Each interface on which OSPFv3 is enabled has a cost associated with it. The Brocade device
advertises its interfaces and their costs to OSPFv3 neighbors. For example, if an interface has an
OSPF cost of ten, the Brocade device advertises the interface with a cost of ten to other OSPF
routers.
By default, an interface’s OSPF cost is based on the port speed of the interface. The software uses
the following formula to calculate the cost:
Cost = reference-bandwidth/interface-speed
By default, the reference bandwidth is 100 Mbps. If the resulting cost is less than 1, the software
rounds the cost up to 1. The default reference bandwidth results in the following costs:
• 10 Mbps port’s cost = 100/10 = 10
• 100 Mbps port’s cost = 100/100 = 1
• 1000 Mbps port’s cost = 100/1000 = 0.10, which is rounded up to 1
• 155 Mbps port’s cost = 100/155 = 0.65, which is rounded up to 1
• 622 Mbps port’s cost = 100/622 = 0.16, which is rounded up to 1
• 2488 Mbps port’s cost = 100/2488 = 0.04, which is rounded up to 1
The bandwidth for interfaces that consist of more than one physical port is calculated as follows:
• Trunk group – The combined bandwidth of all the ports.
• Virtual (Ethernet) interface – The combined bandwidth of all the ports in the port-based VLAN
that contains the virtual interface.