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Configuring a Cisco Network Switch

· 2 min read
Mecken Swyter
Mecken Swyter
Passionate technologist and lifelong learner

This is a basic guide on configuring a Cisco network switch using the CLI (Command-line interface). Most of the examples provided in this guide will be performed using Cisco Packet Tracer.

Initial switch configuration​

When first connecting to the switch, we start in user EXEC mode. This is a very limited mode. Enter the enable command to elevate to Privileged EXEC mode.

Switch>enable
Switch#

Now that we are in Privileged EXEC mode, we need to elevate to Global Configuration mode to configure the switch.

Switch#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#
tip

When a command is entered incorrectly, Cisco IOS will get hung up attempting to resolve the mistyped command to an IP address and require Ctrl +Shift+ 6 to break out of it. The following command will prevent this behavior.

Switch(config)#no ip domain-lookup

A Cisco switch comes with a default name of Switch, the default name can be changed by running the following command. Notice how the start of the command prompt now starts with S1.

Switch(config)#hostname S1
S1(config)#

Console Password: Add a password to the console session.

S1(config)#line console 0
S1(config-line)#password cisco
S1(config-line)#login

Privilege EXEC Password: Add a password to privilege EXEC mode.

S1(config)#enable secret cisco
info

Show Running Config: Verify passwords were configured correctly by stepping back down to Privileged EXEC and run:

S1#show running-config

⚠️ Create a MOTD Banner: Warn against unauthorized access using a MOTD (Message of the Day) banner.

S1(config)#banner motd "Authorized access only. Violators will be prosecuted to the full extent of the law."

Configure an IP on an Interface: Add an IP address to the default Vlan 1 interface.

S1(config)#interface vlan 1
S1(config-if)#ip address 192.168.1.253 255.255.255.0
S1(config-if)#no shutdown

S1(config-if)#
%LINK-5-CHANGED: Interface Vlan1, changed state to up

%LINEPROTO-5-UPDOWN: Line protocol on Interface Vlan1, changed state to up
info

Verify IP addressing by running show ip interface brief

S1#show ip interface brief


FastEthernet0/22       unassigned      YES manual down                  down 
FastEthernet0/23       unassigned      YES manual down                  down 
FastEthernet0/24       unassigned      YES manual down                  down 
GigabitEthernet0/1     unassigned      YES manual down                  down 
GigabitEthernet0/2     unassigned      YES manual down                  down
Vlan1                  192.168.1.253   YES manual up                    up