The procedure in this section applies to the router cards, the modular or fixed configuration switches, and GL-3 Catalyst series switches running Cisco IOS Software.
Router cards:
WS-X4232-L3 (Catalyst 4006/4000)
RSM/RSFC (Catalyst 5500/5000)
MSFC/MSM (Catalyst 6500/6000)
Catalyst modular switches:
Catalyst 6500/6000
Catalyst 4500/4000
Catalyst fixed configuration switches
Catalyst 2940
Catalyst 2950/2955
Catalyst 2970
Catalyst 3550
Catalyst 3560
Catalyst 3750
Catalyst 2900XL/3500XL
GL-3 Catalyst switches:
Catalyst 2948G-L3
Catalyst 4908G-L3
Reset Switch Configuration
1. Type in “write erase” to erase the NVRAM filesystem:
Switch#wr erase Erasing the nvram filesystem will remove all configuration files! Continue? [confirm] [OK] Erase of nvram: complete Switch#
2. When that’s finished, type in “reload” and do NOT save the config:
Switch#reload *Mar 2 05:51:10.245: %SYS-7-NV_BLOCK_INIT: Initialized the geometry of nvrameload Proceed with reload? [confirm] *Mar 2 05:51:14.062: %SYS-5-RELOAD: Reload requested by console. Reload reason: Reload command Using driver version 1 for media type 1 Base ethernet MAC Address: 18:ef:63:70:d6:00 Xmodem file system is available. The password-recovery mechanism is enabled. Initializing Flash... mifs[2]: 0 files, 1 directories mifs[2]: Total bytes : 3870720 mifs[2]: Bytes used : 1024 mifs[2]: Bytes available : 3869696 mifs[2]: mifs fsck took 0 seconds. mifs[3]: 416 files, 8 directories mifs[3]: Total bytes : 27998208 mifs[3]: Bytes used : 13362176 mifs[3]: Bytes available : 14636032 mifs[3]: mifs fsck took 6 seconds. ...done Initializing Flash. done. Loading "flash:/c3750-ipbasek9-mz.122-50.SE1/c3750-ipbasek9-mz.122-50.SE1.bin"...@@@@@@@@@
Reset VLAN Information
1. Type in “show vlan” to see if there are any VLANs configured:
Switch#sh vlan br VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa1/0/1, Fa1/0/2, Fa1/0/3 Fa1/0/4, Fa1/0/5, Fa1/0/6 Fa1/0/7, Fa1/0/8, Fa1/0/9 Fa1/0/10, Fa1/0/11, Fa1/0/12 Fa1/0/13, Fa1/0/14, Fa1/0/15 Fa1/0/16, Fa1/0/17, Fa1/0/18 Fa1/0/19, Fa1/0/20, Fa1/0/21 Fa1/0/22, Fa1/0/23, Fa1/0/24 Gi1/0/1, Gi1/0/2 10 HR active 50 PRINTERS active 99 VOIP active 100 IT active 999 Remote-Span active 1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup 1005 trnet-default act/unsup Switch#
2. Next type in “dir flash:” to verify the vlan.dat file
Switch#dir flash: Directory of flash:/ 2 -rwx 756 Mar 1 1993 04:47:02 +00:00 vlan.dat !--- This vlan.dat file stores user-configured VLANs. 3 drwx 512 Mar 1 1993 00:12:38 +00:00 c3750-ipbasek9-mz.122-50.SE1 27998208 bytes total (14636032 bytes free) Switch#
3. Delete the “vlan.dat” file
Switch#delete flash:vlan.dat Delete filename [vlan.dat]? Delete flash:vlan.dat? [confirm] Switch#
4. Reload once again
Switch#reload Proceed with reload? [confirm] *Mar 1 00:24:17.621: %SYS-5-RELOAD: Reload requested by console. Reload reason: Reload command
5. Now just confirm that the VLANs are gone and we are back to a factory default setting
Switch#sh vlan *Mar 1 00:02:02.272: %LINK-5-CHANGED: Interface Vlan1, changed state to administratively downbr VLAN Name Status Ports ---- -------------------------------- --------- ------------------------------- 1 default active Fa1/0/1, Fa1/0/2, Fa1/0/3 Fa1/0/4, Fa1/0/5, Fa1/0/6 Fa1/0/7, Fa1/0/8, Fa1/0/9 Fa1/0/10, Fa1/0/11, Fa1/0/12 Fa1/0/13, Fa1/0/14, Fa1/0/15 Fa1/0/16, Fa1/0/17, Fa1/0/18 Fa1/0/19, Fa1/0/20, Fa1/0/21 Fa1/0/22, Fa1/0/23, Fa1/0/24 Gi1/0/1, Gi1/0/2 1002 fddi-default act/unsup 1003 token-ring-default act/unsup 1004 fddinet-default act/unsup 1005 trnet-default act/unsup Switch#
If you can not get into the switch, reset it pressing the MODE button:
Follow these steps to return your switch to the factory default settings:
1. 
Press and hold the Mode button.
The switch LEDs begin blinking after about 2 seconds. If the switch is not configured, the LEDs above the mode button turn green. You can omit this step and run Express Setup to configure the switch.
2. Continue holding down the Mode button. The LEDs stop blinking after an additional 8 seconds, and then the switch reboots.
The switch now behaves like an unconfigured switch. You can configure the switch by using Express Setup as described in the switch getting started guide that is included with the switch.