How to Clear Switch Configuration
To clear switch configuration
Issue the erase starting-config command.
Switch#erase startup-config Erasing the nvram filesystem will remove all configuration files! Continue? [confirm] [OK] Erase of nvram: complete Switch#
At this stage, the switch configuration has reset to the factory defaults, with the exclusion of the VLAN information. VLANs are kept in a seperate file from the startup-config (NVRAM).
To verify the VLAN information
Issue the show vlan brief command
Switch#show vlan brief
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
Gi0/1, Gi0/2
10 Faculty/Staff active 20 Students active 30 Wireless active 99 Management active 1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup 1005 trnet-default act/unsup Switch#
Delete the VLAN information from Flash
Switch#delete flash:vlan.dat Delete filename [vlan.dat]? Delete flash:vlan.dat? [confirm]
Switch#
Reload the switch
Do not save at the prompt. Otherwise, the switch reloads with the current running configuration and does not clear the switch configuration.
Switch#reload
System configuration has been modified. Save? [yes/no]: n Proceed with reload? [confirm]
<output omitted>
Would you like to terminate autoinstall? [yes]: y
--- System Configuration Dialog ---
Would you like to enter the initial configuration dialog? [yes/no]: n Switch>
After reload
check the VLAN information with the show vlan brief command.
Switch#show vlan brief
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
Gi0/1, Gi0/2
1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup 1005 trnet-default act/unsup Compiled Thu 19-Jul-07 20:06 by nachen