Cisco Routers VIP Cards and Serial Interface Commands


Cisco Routers VIP Cards

Recently we have made posts on how to bring up a cisco router interface and also how to add An IP address to a cisco router  interface but in the case that  you have a cisco router model 7000 or the 7500 series router with Cisco Routers VIP Cards (Versatile Interface Processor) cards, you define an interface by using the interface type slot/ port adapter/port number.


Serial Interface Commands

For you to able to configure a serial interface, there are a couple of most important things or piece that needs to be added before moving forward.

Typically, the interface will be attached to a CSU/DSU type of device that provides clocking for the line. However, if you have a back-to-back configuration that are widely used in a lab environments, which makes, one end of the router interface to provide clocking.


This would be the DCE end of the cable. Cisco routers, by default, are all DTE devices, and you must specify  an interface to provide clocking if it is to act as a DCE device. To configure a DCE serial interface use the clock rate command from the global configuration mode.


Router#config t

Enter configuration commands, one per line. End with



Router(config)#int s0

Router(config-if)#clock rate ?

Speed (bits per second) once the command is input all the clockrate will appear <300-4000000> it is then left for you to choose clockrate from list.

For this blog purpose I choose 64000 to make my speed even better.

Router(config-if)#clock rate 64000

%Error: The error  command applies only to DCE interfaces

Router(config-if)#int s1

 Router(config-if)#clock rate 64000

Note: It does not hurt anything to try and put a clock rate on an interface. Also note that the clock rate command is in bits per second.

The next command you need to understand is the bandwidth command.

Every Cisco router comes in fully equipped with a default serial link bandwidth of a T1, or 1.544Mbps. However, the important thing here is to understand that this has nothing to do with how data is transferred over your network. We will be using the  bandwidth of a serial link during our main routing configuration protocols such as IGRP, EIGRP, and OSPF to calculate the best cost to a remote network. If you are using RIP routing, then the bandwidth setting of a serial link is not really necessary.


Router(config-if)#bandwidth ?

<1-10000000> Bandwidth in kilobits

Router(config-if)#bandwidth 64

 From the commands above notice that unlike the clock rate command, the bandwidth command is configured in kilobits.

So in conclusion this how you can simply approach Cisco Routers VIP Cards and Serial Interface Commands.

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