Bandwidth and Clock Rate on Serial Interfaces

In Cisco routers, the bandwidth command is used to specify the bandwidth of an interface and the clock rate command is used to specify the clock rate for serial interfaces.

The bandwidth command is used to tell the router the bandwidth of the interface. This command is used to calculate the metric for routing protocols like OSPF and EIGRP. The bandwidth command is used in the following format:

Router(config-if)# bandwidth [bandwidth in kbps]

The clock rate command is used to specify the speed of the serial connection between two routers. This command is used only on the DCE end of the connection. The clock rate command is used in the following format:

Router(config-if)# clock rate [speed in bps]

The clock rate command is used only on serial interfaces that are acting as DCE (data circuit-terminating equipment) interfaces. DCE interfaces are responsible for providing the clock signal for the line. DTE (data terminal equipment) interfaces receive the clock signal from the DCE interface.