Configuration Guide User guide

1252 FastIron Configuration Guide
53-1002494-01
Configuring OSPF
NOTE
If you specify the cost for an individual interface, the cost you specify overrides the cost calculated
by the software.
Interface types to which the reference bandwidth does not apply
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 0.
• 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 not affected by the auto-cost feature.
Changing the reference bandwidth
To change the reference bandwidth, enter the auto-cost reference-bandwidth command at the
OSPF configuration level of the CLI.
Brocade(config-ospf-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 <num>
The <num> parameter specifies the reference bandwidth and can be a value from 1 through
4294967. The default is 100. For 10 Gbps OSPF interfaces, in order to differentiate the costs
between 100 Mbps, 1000 Mbps, and 10,000 Mbps interfaces, set the auto-cost reference
bandwidth to 10000, whereby each slower link is given a higher cost
To restore the reference bandwidth to its default value and thus restore the default costs of
interfaces to their default values, enter the following command.
Brocade(config-ospf-router)#no auto-cost reference-bandwidth
Defining redistribution filters
Route redistribution imports and translates different protocol routes into a specified protocol type.
On Brocade routers, redistribution is supported for static routes, OSPF, RIP, and BGP4. When you
configure redistribution for RIP, you can specify that static, OSPF, or BGP4 routes are imported into
RIP routes. Likewise, OSPF redistribution supports the import of static, RIP, and BGP4 routes into
OSPF routes. BGP4 supports redistribution of static, RIP, and OSPF routes into BGP4.