For password recovery:

Press the STOP and A keys simultaneously, or, on an ASCII terminal or emulator, send a to halt the operating system, if it's running.

Boot single-user from CD-ROM (boot cdrom -s) or network install/jumpstart server (boot net -s).

Mount the root partition on "/a". "/a" is an empty mount point that exists at this stage of the installation procedure. For example: #mount

/dev/dsk/c0t0d0s0 /a

If the mount command fails and since "/a" always exists, then you either typed in the wrong device, OR the system is seeing the root partition as something else.

Set your terminal type so you can use a full-screen editor, such as vi. You can skip this step if you know how to use "ex" or "vi" from open mode. If you're on a sun console, type "TERM=sun; export TERM"; If you are using an ascii terminal or terminal emulator on a PC for your console, set TERM to the terminal type for example: TERM=vt100; export TERM.

Edit the passwd file, /a/etc/shadow (or perhaps in older versions,

/etc/passwd) and remove the encrypted password entry for root.

Type: "cd /; then "umount /a"

Reboot as normal in single-user mode ("boot -s"). The root account will not have a password. Give it a new one using the passwd command.

http://www.cisco.com/en/US/docs/voice_ip_comm/pgw/9/release/note/rn932.html

http://www.cisco.com/en/US/products/hw/vcallcon/ps2027/products_configuration_example09186a008022e827.shtml