Basic Cisco Switch Configuration.
Configuring Cisco switches is much easier to routers. Layer 3 switches are designed to route packets between different LAN segments similarly to dedicated routers. However, Layer 3 switches do not completely replace the need for routers on a network.
Routers perform additional Layer 3 services that Layer 3 switches are not capable of performing. Routers are also capable of performing packet forwarding tasks not found on Layer 3 switches, such as establishing remote access connections to remote networks and devices. Dedicated routers are more flexible in their support of WAN interface cards (WIC), making them the preferred, and sometimes only, choice for connecting to a WAN. Layer 3 switches can provide basic routing functions in a LAN and reduce the need for dedicated routers.
This page includes basic feature-by-feature configuration procedures, I must assume you have generated you IP addressing scheme for your network.
After your switch boots, the following prompt displays:
Press RETURN to get started! (Hit the enter key will take you into the User EXEC. MODE
Switch> (type enable and hit the ENTER key to go into the Privilege EXEC. MODE)
Switch#
In this mode you could ask or query (argument) the switch for some information like:
Show ? –
The router will provide a list of information on its configuration which most times are very helpful.
Using the Help Facility
Context Sensitive HelpThe Cisco IOS CLI (command line interface) offers two types of help:
Word help: If you can’t remember an entire command but do remember the first few characters, enter the character sequence followed by a question mark (?). Do not include a space before the question mark.
A list of commands that start with the characters that you entered is displayed. For example, entering sh? returns a list of all commands that begin with the sh character sequence.
Command syntax help: If you are unfamiliar with which commands are available in your current context within the Cisco IOS CLI, or if you do not know the parameters required or available to complete a given command, enter the ? command.
When only ? is entered, a list of all available commands in the current context is displayed. If the ? command is entered after a specific command, the command arguments are displayed. If <cr> is displayed, no other arguments are needed to make the command function. Make sure to include a space before the question mark to prevent the Cisco IOS CLI from performing word help rather than command syntax help. For example, enter show ? to get a list of the command options supported by the show command.
For example:-
Switch>enable
Switch#show ?
arp Arp table
boot show boot attributes
cdp CDP information
lock Display the system clock
dtp DTP information
* * * * * *
Switch#show
The above display shows the Cisco help functions.
Using the example of setting the device clock, let's see how CLI help works. If the device clock needs to be set but the clock command syntax is not known, the context-sensitive help provides a means to check the syntax.
Context-sensitive help supplies the whole command even if you enter just the first part of the command, such as cl?.
If you enter the command clock followed by the Enter key, an error message indicates that the command is incomplete. To view the required parameters for the clock command, enter ?, preceded by a space. In the clock ? example, the help output shows that the keyword set is required after clock.
If you now enter the command clock set, another error message appears indicating that the command is still incomplete. Now add a space and enter the ? command to display a list of command arguments that are available at that point for the given command.
The additional arguments needed to set the clock on the device are displayed: the current time using hours, minutes, and seconds.
Type ‘config terminal’ and hit the enter key to take you into Global configuration mode :-
Switch1(config)#
In this mode :
i. You can name your switch or hostname
ii. Configure your telnet line and console lines
iii. Configure the Console and Telnet passwords.
iv. Create Vlans and VTPs
v. Interface configurations, Routing Protocols, etc.
Lets do it one after the other:
Configuring Telnet line and Password:
Switch1(config)#enable secret cisco
Switch1(config)#line vty 0 15
Switch1(config-line)#password cisco
Switch1(config-line)#login
Switch1(config-line)#exit
Configuring Console line and Password:
Switch1(config)#line con 0
Switch1(config-line)#password cisco
Switch1(config-line)#login
Switch1(config-line)#exit
Configuring hostname on a Switch :
Switch1(config)#hostname BRANCH1
BRANCH1(config)#exit
You may have noticed how the Switch name has changed from switch to BRANCH1.
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