Dell PowerConnect FCS624S Configuration Guide - Page 989

Configuring OSPF 29 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 a command such as the following at the OSPF configuration level of the CLI. PowerConnect(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 The 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. PowerConnect(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 Dell 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. NOTE The Layer 3 Switch advertises the default route into OSPF even if redistribution is not enabled, and even if the default route is learned through an IBGP neighbor. IBGP routes (including the default route) are not redistributed into OSPF by OSPF redistribution (for example, by the OSPF redistribute command). PowerConnect B-Series FCX Configuration Guide 947 53-1002266-01