http://www.cisco.com/JP/support/public/ht/tac/100/1007864/156-j.shtml
Erase Configuration.
Router# <kbd>write erase</kbd>
Erasing the nvram filesystem will remove all configuration files! Continue? [confirm]<kbd>y</kbd>
Erase of nvram: complete
Router# <kbd>reload</kbd>
System configuration has been modified. Save? [yes/no]: <kbd>n</kbd>
Proceed with reload? [confirm] <kbd>y</kbd>
：
：
--- System Configuration Dialog ---
Would you like to enter the initial configuration dialog? [yes/no]: <kbd>n</kbd>
Press RETURN to get started!
Erase VLAN database.
Router# <kbd>show vlan-switch</kbd>
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Fa2, Fa3, Fa4, Fa5, Fa6, Fa7
Fa8, Fa9
10 VLAN0010 active
30 VLAN0030 active
50 VLAN0050 active
70 VLAN0070 active
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 1002 1003
10 enet 100010 1500 - - - - - 0 0
30 enet 100030 1500 - - - - - 0 0
50 enet 100050 1500 - - - - - 0 0
70 enet 100070 1500 - - - - - 0 0
--More--
Router# <kbd>dir flash:</kbd>
Directory of flash:/
1 -rw- 23652152 Nov 15 2010 22:44:14 +00:00 c181x-advipservicesk9-mz.124-24.T4.bin
2 -rw- 900 Nov 25 2010 14:34:28 +00:00 vlan.dat
64020480 bytes total (40361984 bytes free)
Router# <kbd>delete flash:vlan.dat</kbd>
Delete filename [vlan.dat]? <kbd>Enter</kbd>
Delete flash:/vlan.dat? [confirm]<kbd>y</kbd>
Router# <kbd>reload</kbd>
Proceed with reload? [confirm]<kbd>y</kbd>
：
：
--- System Configuration Dialog ---
Would you like to enter the initial configuration dialog? [yes/no]: <kbd>no</kbd>
Press RETURN to get started!