Brocade FastIron Ethernet Switch Layer 3 Routing Configuration Guide - Manual (Page 328)

The interfaces that consist of more than one physical port is calculated as follows:
• LAG 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.
You can change the default reference bandwidth from 100 Mbps to a value from 1 through 4294967.
If a change to the reference bandwidth results in a cost change to an interface, the Brocade device
sends a link-state update to update the costs of interfaces advertised by the Brocade device.
NOTE
If you specify a cost for an interface, your specified cost overrides the cost that the software
calculates.
Some interface types are not affected by the reference bandwidth and always have the same cost
regardless of the reference bandwidth in use:
• The cost of a loopback interface is always 1.
• The cost of a virtual link is calculated using the Shortest Path First (SPF) algorithm and is not
affected by the auto-cost feature.
• The bandwidth for tunnel interfaces is 9 Kbps and is subject to the auto-cost feature.
For example, to change the reference bandwidth to 500, enter the following command.
device(config-ospf6-router)# auto-cost reference-bandwidth 500
The reference bandwidth specified in this example results in the following costs:
• 10 Mbps port cost = 500/10 = 50
• 100 Mbps port cost = 500/100 = 5
• 1000 Mbps port cost = 500/1000 = 0.5, which is rounded up to 1
• 155 Mbps port cost = 500/155 = 3.23, which is rounded up to 4
• 622 Mbps port cost = 500/622 = 0.80, which is rounded up to 1
• 2488 Mbps port cost = 500/2488 = 0.20, which is rounded up to 1
The costs for 10 Mbps, 100 Mbps, and 155 Mbps ports change as a result of the changed reference
bandwidth. Costs for higher-speed interfaces remain the same.
Syntax: [no] auto-cost reference-bandwidth number
The number parameter specifies the reference bandwidth in the range from 1 through 4294967. The
default is 100.
To restore the reference bandwidth to its default value and thus restore the default costs of the
interfaces to their default values, enter the no form of this command.
Redistributing routes into OSPFv3
In addition to specifying which routes are redistributed into OSPFv3, you can configure the following
aspects related to route redistribution:
• Default metric.
• Metric type.
• Advertisement of an external aggregate route.
Redistributing routes into OSPFv3
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