Infrastructure


Basic Configuration of a CISCO switch

Three command can be used to logout from terminal.

Switch>enable
Switch#disable
Switch>exit

Switch con0 is now available

Press RETURN to get started.

show version Command will display the device platform, detected interface, ios name

Switch>enable
Switch#show version
Cisco IOS Software, C2960 Software (C2960-LANBASE-M), Version
12.2(25)FX, RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2005 by Cisco Systems, Inc.
Compiled Wed 12-Oct-05 22:05 by pt_team
ROM: C2960 Boot Loader (C2960-HBOOT-M) Version 12.2(25r)FX,
RELEASE SOFTWARE (fc4)
System returned to ROM by power-on
Cisco WS-C2960-24TT (RC32300) processor (revision C0) with
21039K bytes of memory.
24 FastEthernet/IEEE 802.3 interface(s)
2 Gigabit Ethernet/IEEE 802.3 interface(s)

[Output is omitted]

show mac address Command will show all detected mac address dynamically and manually

Switch#show mac-address-table
          Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----

   1    0001.643a.5501    DYNAMIC     Gig1/1

To view run time configuration of RAM use show running-config command

Switch#show running-config
Building configuration...
Current configuration : 925 bytes
version 12.2
no service password-encryption
!
hostname Switch

[Output is omitted]

To view startup configuration [ Stored in NVRAM] use show startup-config command

Switch#show startup-config
Current configuration : 925 bytes
version 12.2
no service password-encryption
!
hostname Switch

[Output is omitted]

To get information about VLAN configuration use show vlan command

Switch#show vlan

VLAN Name                      Status    Ports
---- -------------------------------- --------- -----------------------
1    default                   active    Fa0/1, Fa0/2, Fa0/3, Fa0/4
                                         Fa0/5, Fa0/6, Fa0/7, Fa0/8
                                         Fa0/9, Fa0/10, Fa0/11, Fa0/12
                                         Fa0/13, Fa0/14, Fa0/15, Fa0/16
                                         Fa0/17, Fa0/18, Fa0/19, Fa0/20
                                         Fa0/21, Fa0/22, Fa0/23, Fa0/24
[Output is omitted]

show interface command will show all detected interface with their hardware description and configuration

Switch#show interfaces
FastEthernet0/1 is up, line protocol is up (connected)
  Hardware is Lance, address is 0060.2f9d.9101 (bia 0060.2f9d.9101)
  MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
[Output is omitted]

interface vlan 1 is used to assign ip address and default gateway to switch. Show interface vlan 1 will give a over view of vlan1.

Switch#show interface vlan1
Vlan1 is administratively down, line protocol is down
  Hardware is CPU Interface, address is 0060.5c23.82ae
   (bia 0060.5c23.82ae)
  MTU 1500 bytes, BW 100000 Kbit, DLY 1000000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  ARP type: ARPA, ARP Timeout 04:00:00

[Output is omitted]

delete command is used to delete all vlan configuration from switch Don’t add space between flash and vlan.dat Run this exactly shown here adding a space could erase flash entirely leaving switch blank

Switch#delete flash:vlan.dat
Delete filename [vlan.dat]?
Delete flash:/vlan.dat? [confirm]
%deleting flash:/vlan.dat

Startup configuration can be removed by erase commands

Switch#erase startup-config
Erasing the nvram filesystem will remove all configuration files!
Continue? [confirm]
[OK]
Erase of nvram: complete
%SYS-7-NV_BLOCK_INIT: Initialized the geometry of nvram

Basic Switch Configuration Step by Step

use configure terminal command to go in global configuration mode

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

Now change default switch name to switch 1

Switch(config)#hostname Switch1

Set enable password to vinita and secret to nikki

Switch1(config)#enable password vinita
Switch1(config)#enable secret nikki

Set console password to vinita and enable it by login command. Order of command is important. Set password before you enable it.

Switch1(config)#line console 0
Switch1(config-line)#password vinita
Switch1(config-line)#login
Switch1(config-line)#exit

Enable 5 telnet session [ vty0 – vty4] for router and set their password to vinita

Switch1(config)#line vty 0 4
Switch1(config-line)#password vinita
Switch1(config-line)#login
Switch1(config-line)#exit

Now set switch ip address to 192.168.0.10 255.255.255.0 and default gateway to 192.168.0.5

Switch1(config)#interface vlan1
Switch1(config-if)#ip address 192.168.0.10 255.255.255.0
Switch1(config-if)#exit
Switch1(config)#ip default-gateway 192.168.0.5

Set a description finance VLAN to interface fast Ethernet 1

Switch1(config)#interface fastEthernet 0/1
Switch1(config-if)#description finance VLAN

By default switch automatically negotiate speed and duplex but you can adjust it manually

Switch1(config-if)#duplex full
%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1,
 changed state to downSwitch1
(config-if)#duplex auto
%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up
Switch1(config-if)#duplex half
%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to down
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1,
changed state to down
%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up
Switch1(config-if)#duplex auto
Switch1(config-if)#speed 10
Switch1(config-if)#speed 100
Switch1(config-if)#speed auto
Switch1(config-if)#exit
Switch1(config)#exit

mac address table can be wiped out by clear commands

Switch1#show
Switch1#show mac-address-table
          Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----

   1    0001.643a.5501    DYNAMIC     Gig1/1
Switch1#clear mac-address-table
Switch1#clear mac-address-table ?
  dynamic  dynamic entry type
Switch1#clear mac-address-table dynamic

To restart switch use reload command [ running configuration will be erased so copy it first to startup configuration ]

Switch1#reload
Proceed with reload? [confirm]
Switch con0 is now available
Press RETURN to get started.