Comando Basicos De Un Switch

Comandos Básicos de Switch Catalyst 2950

Lab 6.14: Connecting to the 2950 Switch and Setting Passwords

This lab will have you connect to a 2950 switch, enter global configuration mode and then set the passwords.

1. Open up a 2950 switch from the RouterSim Network Visualizer screen.

2. Press enter to connect to the console

Switch>

3. For the usermode of the switch, you can use the help screen just like a router.

Switch>?

Exec commands:

<1-99> Session number to resume

access-enable Create a temporary Access-List entry

clear Reset functions

connect Open a terminal connection

disable Turn off privileged commands

disconnect Disconnect an existing network connection

enable Turn on privileged commands

exit Exit from the EXEC

help Description of the interactive help system

lock Lock the terminal

login Log in as a particular user

logout Exit from the EXEC

name-connection Name an existing network connection

ping Send echo messages

rcommand Run command on remote switch

resume Resume an active network connection

show Show running system information

systat Display information about terminal lines

telnet Open a telnet connection

terminal Set terminal line parameters

traceroute Trace route to destination

tunnel Open a tunnel connection

--More--

4. The first thing that you should configure on a switch is the passwords. You don’t want unauthorized users connecting to the switch. You can set both the user mode and privileged mode passwords, just like a router. Enter enable mode by using the enable command and then enter global configuration mode by using the config t command. The switch following output shows an example of how to get into enable mode, and then into global configuration mode.

Switch>enable

Switch#config t

Enter configuration commands, one per line. End with CTRL/Z

Switch(config)#

5. Once you are in global configuration mode, you can set the user mode and enable mode passwords by using the enable password and enable secret command. The switches output below shows the configuration of both the user mode and enable mode passwords.

Switch(config)#enable password ?

0 Specifies an UNENCRYPTED password will follow

7 Specifies a HIDDEN password will follow

LINE The UNENCRYPTED (cleartext) 'enable' password

level Set exec level password

Switch(config)#enable password todd

Switch(config)#enable secret cisco

Switch(config)

6. Remember, if you set your enable secret, the enable password is superceded and not used, just like in a router.

7. In addition to the enable password and enable secret, the 2950 allows you to set a console and telnet password as well using the line commands, just like in a router.

Switch(config)line ?

<0-16> First Line number

console Primary terminal line

vty Virtual terminal

Switch(config)#line console 0

Switch(config-line)# password console

Switch(config-line)#login

Switch(config-line)#line vty ?

% Unrecognized command

8. Remember that just like in a router, you cannot get help for a line command from within line configuration mode. Type exit to go back one step.

Switch(config-line)#exit

Switch(config)#line vty ?

<0-15> First Line number

Switch(config)#line vty 0 15

Switch(config-line)# password telnet

Switch(config-line)#login

Switch(config-line)#cntrl+z

Switch#

9. You can use show running-config (show run for short) to see the current configuration on the switch.

Current configuration : 997 bytes

!

version 12.1

no service pad

service timestamps debug uptime

service timestamps log uptime

no service password-encryption

!

hostname Switch

!

enable secret 5 $1$yNgO$9uU0Z6NG1ib4vlt05bmMW1

enable password todd

!

ip subnet-zero

!

spanning-tree extend system-id

!

!

interface FastEthernet0/1

no ip address

!

interface FastEthernet0/2

no ip address

--More--

Notice the enable mode password is not encrypted by default, but the enable secret is. This is the same password configuration technique that you will find on a router.

Lab 6.15: Setting the Hostname on a 2950 Switch

The hostnames on a switch, as well as on a router, is only locally significant. This means that it doesn’t have any function on the network or used for name resolution whatsoever. However, it is helpful to set a hostname on a switch so that you can identify the switch when connecting to it. A good rule of thumb is to name the switch after the location it is serving.

1. The 2950 switch command to set the hostname is exactly like any router: you use the hostname command. Remember, it is one word. From global configuration mode, type the command hostname hostname.

Switch>enable

Enter password: ****

Switch#config t

Enter configuration commands, one per line. End with CTRL/Z

Switch(config)#hostname Todd2950A

Todd2950A(config)#exit

Todd2950A#

Notice that as soon as I pressed enter, the hostname of the switch appeared. Remember that from global configuration mode, which you enter by using the config t command, it changes the running-config. Any changes you make in this mode take effect immediately.

Lab 6.16: Configuring IP Address Information on a 2950 Switch

You do not have to set any IP configuration on the switch to make it work. You can just plug in devices and they should start working, just like they would on a hub. The reason you would set the IP address information on the switch is so you can either manage the switch via Telnet or other management software, or you wanted to configure the switch with different VLANs and other network functions. VLANs are discussed later in this chapter.

1. By default, no IP address or default-gateway information is set. You would set both the IP address and the default-gateway on a layer-two switch, just like any host. By typing the command show running-config you can see the default IP configuration of the switch. Notice in your switch output that no IP address, default-gateway, or other IP parameters are configured.

2. To set the IP configuration on a 2950 switch, use the ip address command. However, this is set under the VLAN1 interface, not at global configuration mode like on a 1900 switch. Remember that by default all interfaces are members of VLAN1, which is why the VLAN1 interface is configured by default.

Todd2950A#config t

Enter configuration commands, one per line. End with CTRL/Z

Todd2950A(config)#interface vlan1

Todd2950A(config-if)#ip address 172.16.10.17 255.255.255.0

Todd2950A(config-if)#exit

Todd2950A(config)#exit

Todd2950A#

3. The default gateway should also be set using the ip default-gateway command. However, unlike the IP address, this is completed at global configuration mode.

Todd2950A#config t

Enter configuration commands, one per line. End with CTRL/Z

Todd2950A(config)#ip default-gateway 172.16.10.1

Todd2950A(config)#exit

Todd2950A#

To change the IP address and default-gateway on the switch, you can either type in new addresses or remove the IP information with the no ip address and no ip default-gateway commands, at the appropriate configuration prompt.

Lab 6.17: Configuring 2950 Switch Interfaces

It is important to understand how to access switch ports. The 2950 switch uses the type slot/port command, just like a 2600 router and just like the 1900 switch. For example, Fastethernet 0/3 is 10/100BaseT port 3.

The 2950 switch type slot/port command can be used with either the interface command or the show command. The interface command allows you to set interface specific configurations. The 2950 switch has only one slot: zero (0), just like the 1900.

1. To configure an interface on a 1900 switch, go to global configuration mode and use the interface command as shown.

Todd2950A#config t

Enter configuration commands, one per line. End with CTRL/Z

Todd2950A(config)#interface ?

Async Async interface

BVI Bridge-Group Virtual Interface

Dialer Dialer interface

FastEthernet FastEthernet IEEE 802.3

Group-Async Async Group interface

Lex Lex interface

Loopback Loopback interface

Multilink Multilink-group interface

...