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