As much as I hate to admit it I’ve royally messed up a pretty good amount of Cisco switch configs and at times I just wanted to start over. One tiny little thing I ran into at first is just resetting the switch doesn’t clear EVERYTHING!!! Those pesky VLANs stay on the switch because they are in a separate file called vlan.dat which is different from where the startup-config (NVRAM) resides.

Well here’s how to clear a switch back to the facory defaults – the easy way and the REALLY easy way:

The Easy Way

Switch# write erase
Switch# delete flash:vlan.dat
Delete filename [vlan.dat]?
!--- Press Enter
Delete flash:/vlan.dat? [confirm]
Switch# reload

The REALLY Easy Way

• Hold the “mode” button on the front of the switch for 10 seconds.
• The lights will blink then go solid
• The switch completely wipes all configuration and then reboots