In the above formula, the cost is calculated in megabits per second (Mbps). The auto-cost is congured using the auto-cost reference-
bandwidth command in OSPF router conguration mode or OSPFv3 router conguration mode. For more information on changing the
OSPF auto-cost reference-bandwidth, refer to the Changing the reference bandwidth on page 247 section.
Setting the bandwidth value for an Ethernet interface
The current bandwidth value for an Ethernet interface can be set and communicated to higher-level protocols such as OSPF.
1. Enter the
congure terminal command to access global conguration mode.
device# configure terminal
2. Enter the interface ethernet command to
congure an Ethernet interface and enter interface conguration mode.
device(config)# interface ethernet 1/1/1
3. Enter the bandwidth command and specify a value to set the bandwidth value on the interface.
device(config-if-e1000-1/1/1)# bandwidth 2000
This example sets the bandwidth to 2000 kbps on a specic Ethernet interface.
device# configure terminal
device(config)# interface ethernet 1/1/1
device(config-if-e1000-1/1/1)# bandwidth 2000
The bandwidth
specied in this example results in the following OSPF cost, assuming the auto-cost is 100:
• OSPF cost is equal to ((100 * 1000) + (2000 - 1)/ 2000) = 50
Setting the bandwidth value for a VE interface
The current bandwidth value for a VE interface can be set and communicated to higher-level protocols such as OSPF.
1. Enter the congure terminal command to access global conguration mode.
device# configure terminal
2. Enter the vlan command and specify a value to congure a VLAN.
device(config)# vlan 10
3. Enter the tagged ethernet command and specify an interface to add a port that is connected to the device and host in the same
port-based VLAN.
device(config-vlan-10)# tagged ethernet 1/1/1
4. Enter the router-interface ve command and specify a value to create a virtual interface as the routing interface for the VLAN.
device(config-vlan-10)# router-interface ve 10
Creates VE 10 as the routing interface for the VLAN.
5. Enter the interface ve command and specify a value.
device(config-vlan-10)# interface ve 10
Creates a VE interface with the VLAN ID of 10.
Bandwidth for IP interfaces
FastIron Ethernet Switch Layer 3 Routing
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