Configuring the Cisco Catalyst 1900 switch

The Cisco Catalyst 1900 switch is a very useful tool for small workgroups or access closets needing switched 10-Mbps ports. In this Daily Feature, Todd Lammle shows you how they are configured.

The Cisco Catalyst 1900 switch was developed from the old Kalpano switch and is used for small workgroups or access closets that need switched 10-Mbps ports.

There are two Catalyst 1900 switches, the 1912, with 12 10BaseT switched ports and two FastEthernet switched ports, and the 1924 with 24 10BaseT switched ports and two FastEthernet switched ports.

Cisco has created a Command-Line Interface (CLI) for the 1900 series of switches, and it works great. This Daily Feature will show you how to set up a Cisco Catalyst 1900 switch using the CLI.

The Catalyst 1900 CLI
To run the Catalyst CLI, you must make sure the switch is running the correct IOS. The CLI is only available in the Enterprise Edition software, which costs more money than the standard IOS, of course.

When you first start up the switch, all the lights on the switch will turn on and then off during the boot cycle. Then you will get the following menu:
Catalyst 1900 Management Console
Copyright (c) Cisco Systems, Inc.  1993-1999
All rights reserved.
Enterprise Edition Software
Ethernet Address:      00-B0-64-75-64-00

PCA Number:            73-3122-04
PCA Serial Number:     FAB040131E5
Model Number:          WS-C1912-A
System Serial Number:  FAB0401U0JW
Power Supply S/N:      PHI033106HW
PCB Serial Number:     FAB040131E5,73-3122-04

1 user(s) now active on Management Console.

        User Interface Menu

     [M] Menus
     [K] Command Line
     [I] IP Configuration
     [P] Console Password

Enter Selection:

Notice the fourth line from the top, which states that the switch is running Enterprise Edition Software. The last section is the User Interface Menu, which allows you to use the older Menu system [M], Command Line [K] (Why not “C?” Who knows!), IP Configuration [I], or Console Password [P].

Once you choose K from the User Interface Menu, you get the familiar router prompt (>):
Enter Selection:  K

      CLI session with the switch is open.
      To end the CLI session, enter [Exit].


From here, you basically configure the switch like a router, with some small differences, which you will learn about in the next section.

From the > prompt, log in to the router by using the enable command:

Notice that the prompt changed to a pound sign (#), which indicates that you are in privilege mode and can now view and change the switch’s configuration.

To view the configuration on the switch, you can use the show running-config command, just like on a router.
#sh running-config
Building configuration...
Current configuration:
interface Ethernet 0/1

interface Ethernet 0/2


interface Ethernet 0/3

interface Ethernet 0/4

interface Ethernet 0/5

interface Ethernet 0/6

interface Ethernet 0/7

interface Ethernet 0/8

interface Ethernet 0/9


interface Ethernet 0/10

interface Ethernet 0/11

interface Ethernet 0/12

interface Ethernet 0/25

interface FastEthernet 0/26

interface FastEthernet 0/27

line console

The first thing you should notice is that there is not really any configuration on the switch. However, when you connect a switch, it will work in your network without any configuration—a feature that allows you to replace your hubs with switches easily. Also notice that the first 12 ports are named Ethernet 0/1 through 0/12. These are the 10BaseT ports. The FastEthernet ports are named FastEthernet 0/26 and 0/27. The 0/25 port is an AUI connector on the back of the switch for connecting to a Thinnet network (if you can find one in use somewhere).

Setting the hostname, passwords, interface descriptions, switch banner, and IP information
The configuration of the switch is close to the configuration of a router. I will walk you through the configuration of the switch using the CLI, one step at a time.

Setting the hostname of the switch
To configure the hostname of the switch, the command hostname is used from global configuration mode, which is entered by typing the command configure terminal, or config t for short.

Notice that the prompt changed to (config)#, which indicates that you are in global configuration mode. The hostname immediately changes the name of the switch. Understand that the hostname is only locally significant and has nothing to do with how the switch works in the internetwork. It is for identifying the switch to the administrator. For example, you can set the hostname to B3F2C6, which would be Building 3, floor 2, closet 6, which is a nice identifier when someone telnets into the switch.

Set the switch passwords
This is where the switch differs somewhat from a router’s configuration. To set the passwords, you use the enable password level 1 or 15 command. For example, to set the usermode password, the following command is used:
Todd1900(config)#enable password level 1 todd

To set the enable password, use the enable password level 15 command, as shown:
Todd1900(config)#enable password level 15 lammle

In the newer 1900 IOS (v9 or greater), the enable secret password has been added, so we can use the enable secret command instead of the level 15 password. You can see which IOS version you are using with the show version command:

Since this is version 9.00.00, we can use the enable secret password, which is encrypted by default:
Todd1900(config)#enable secret cisco

If you set the enable password level 15 as well as the enable secret, only the enable secret will be used.

Set the switch interface descriptions
To set the switch interface descriptions, which are used to identify to an administrator what is plugged into each port, use the description command.

Notice that an underscore must be used to separate words. You can then view the descriptions with either the show interface command or the show running-config command.

Setting the switch banner
Also new in the 9.x IOS of the switch is the capability to set a switch banner. This is used to give information regarding the location of the switch to an administrator who connects to the switch through a console or telnet session. Although that is a good purpose, you can write whatever you want, for example:
Todd1900(config)#banner motd #
Enter TEXT message.  End with the character '#'.
Everyone send Todd all your money

The MOTD is message of the day, which is a leftover from the UNIX days, when administrators wrote a message to anyone who logged into the network. The pound sign (#) is called a delimiting character. The next time that character is typed, the switch knows that is the end of the message.

Setting the IP configuration
You set the IP information on the switch, just like any host. The confusion for most people is that they try to set the IP address on a switch interface, which is incorrect. Switches do not use IP addresses (except multilayer switches). Instead, they only read the hardware address of a frame to make forward and filtering decisions.

From global config, you set the IP address, mask, and ip default-gateway:
Todd1900(config)#ip address
Todd1900(config)#ip default-gateway

You can then view the configuration with either the show running-config command or the show ip command:
Todd1900#sh ip
IP Address:
Subnet Mask:
Default Gateway:
Management VLAN:  1
Domain name:
Name server 1:
Name server 2:
HTTP server : Enabled
HTTP port :  80
RIP : Enabled

Please do not get confused about setting an IP address on the 1900 switch. The only reason you would set the switch IP address, subnet mask, and default gateway is for management purposes. The IP information has no bearing on how the switch is used within the internetwork.

The 1900 switch is a great little switch for smaller workgroups or access closets in an internetwork. The IOS allows for easy configuration as well as VLAN and trunking configuration with ISL inter-VLAN routing.

The problem with the 1900 switch is the price. The list is around $1200 or so for a new switch, which is high for 12 or 24 ports of switched 10BaseT.

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