Perhaps you’ve forgotten the password to your firewall? This post will answer the question: How do I restore the password on a Cisco ASA?
To recover passwords, perform the following steps:
Console into the ASA.
Reboot the ASA
Press the escape key during reboot to enter ROMMON.
Tell the firewall to ignore the startup config on next reload:
The following will be displayed:
Current Configuration Register: 0x00000011
boot TFTP image, boot default image from Flash on netboot failure
Do you wish to change this configuration? y/n [n]:
Jot down the config register value for later.
yto say yes.
Hit enter at each prompt to accept the default. When you get to “disable system configuration” hit
Reboot the ASA
At this point the ASA should reload and completely bypass the configuration.
When the firewall reboots it will not prompt a console user for a username and the enable password is blank. Go into enable mode.
Restore the old config
copy startup-config running-config
Enter config mode and reset the password
enable password NEW_PASSWORD
username USER password NEW_PASSWORD
Restore the config registry to where it was to begin with. This is the number you wrote down earlier.
Save your config
copy running-config startup-config
At this point you have regained access to the firewall and restored the config file and registry to where it before the password reset.
Link to all Cisco product password recovery pages. http://www.cisco.com/en/US/products/sw/iosswrel/ps1831/products_tech_note09186a00801746e6.shtml