Chapter 2: Basic Switch Configuration

In Depth

Throughout the last decade, Cisco has acquired some major switching vendors such as Kalpana and Crescendo. As a result, Cisco switches have a variety of command−line interfaces you need to be familiar with in order to set up and maintain the devices.

Command−Line Interfaces

The most common interface found on the Cisco Catalyst line of switches is the original Crescendo interface (named for the vendor Cisco purchased). This interface is often termed the Set/Clear command−based switch, because these switches are limited to set, clear, and show commands. The Crescendo interface can be found in the following switches:

∙Catalyst 2900G series

∙Catalyst 2926

∙Catalyst 4000 series

∙Catalyst 5000 series

∙Catalyst 5500 series

∙Catalyst 6000 series

∙Catalyst 6500 series

A second type of interface is found on more recent models. It is called the Command−Line Interface (CLI). The Enterprise Edition Software of these switches uses the standard Cisco Internetwork Operating System (IOS), which is virtually identical to the IOS found on Cisco’s line of routers. The CLI can be found on the following switches:

∙Catalyst 1900 series

∙Catalyst 2820 series

∙Catalyst 2900 XL series

∙Catalyst 8500 GSR series

∙Catalyst 12000 GSR series

A third type of interface is found on Cisco’s legacy switches. These devices have a menu−driven interface that you use to enter commands. The menu selections are fairly intuitive, so you don’t have to memorize a lot of commands to get around the switches. The interface is found on these switches:

∙Catalyst 1900 series

∙Catalyst 2820 series

∙Catalyst 3000 series

On each of the three different interfaces of Cisco Catalyst switch IOSs, you will need to perform certain common configuration tasks in order to configure the switch initially. Unless your switch was preconfigured, in most cases you will need to connect to the console port to begin the initial configuration of the device.

After the switch has been powered on and has completed its power on self test (POST) sequence, it’s a good idea to assign the switch a hostname to help to identify the switch. Doing so is particularly useful if you have multiple switches at multiple layers of the network. You should choose a name that identifies the switch type and its placement in the network. For example, if two Cisco Catalyst 5000 switches are on the third floor of your building, you might want to name the second switch 50002FL3. So long as you use the same naming convention on all the switches in your network, they will be easy to identify when you’re configuring them remotely.

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