Recovering Lost Cisco Passwords

Connect a PC or Terminal to the router's console port using a Terminal Emulation program such as Hyper Terminal (need to update original HyperTerminal for NT (doesn't send break) or use the Win95/98 version).
Once connected and logged in type show version and record the settings of the Configuration register. The configuration register setting is shown at the bottom of the screen in the format of:Configuration Register is 0x2102
With the terminal or PC still attached, power off the router and power on the router.
Within 60 seconds of the router powering back on, press the [Control]+[Break] keys on the keyboard of the terminal.
If done correctly, you should see the bootstrap program prompt > without a router name in the prompt. If you don't see the symbol, the break signal wasn't properly sent to the router. Try it again after checking the console cable and Terminal settings (9600 baud, 8 data bits, No parity, 1 stop bits).
On 2500 series routers, to reset the the configuration register to boot from ROM and ignore NVRAM enter the command at the > prompt: o/r 0x042
Initialize the router by entering the command i at the > prompt.
The Router will go through the power cycle and will set the register to 0x042. This will cause the router to boot the boot ROM system image and prompt you with the system configuration dialog as follows:--System Configuration Dialog--
Answer no to the configuration system prompts until the following is displayed:Press RETURN to get started!
Press [ENTER] and the boot ROM prompt appears:Router>
Enter the enable command at the prompt. Then enter the configure memory command as follows:Router#configure memory
Enter the terminal configuration mode with the command:Router#conf t
Now you can enter your new passwords with the commands: (where ccna is the new password)Router(config)#enable ccnaRouter(config)#enable secret ccna
Set the configuration register back to the original setting with the command:Router(config)#config-register 0x2102
Then enter the following commands to exit global configuration mode, save the configuration, and restart the router.Router(config)#[control]+[Z]Router#write memRouter#reload

Cisco Help and Editing

Enter ? at any prompt to see a complete listing of available commands that can be used at the prompt level. You can also do partial a word to see available commands that start with letters before ? (e.g. s?, cl?, eth?).
When entering commands, you don't have to complete the entire word just enough to make it recognizable to the IOS from any other command. Example: instead of using the show command, you can use sh in place of show and it will work the same.
The ? can also be used to show the next step in the command. If you type a partial command and press the [Tab] key, the command is completed for you automatically. Router_2(config)# int [Tab] Router_2(config)# interface Router_2(config)# interface ? Async Async interface BVI Bridge-Group Virtual Interface Dialer Dialer interface Ethernet IEEE 802.3 Group-Async Async Group interface Lex Lex interface Loopback Loopback interface Null Null interface Port-channel Ethernet Channel of interfaces Serial Serial Tunnel Tunnel interface Virtual-Template Virtual Template interface Virtual-TokenRing Virtual TokenRing Router_2(config)# interface ethernet ? <0-0> Ethernet interface number Router_2(config)# interface ethernet 0 Router_2(config-if)#
Use the [spacebar] to scroll another page if available commands is longer than one page, use the [enter] key to scroll one line at a time. If help page is scrolled, press any key to return to the command line.

Command Line Editing Commands
Command
Meaning
Ctrl+A
Moves cursor to beginning of the line.
Ctrl+E
Moves cursor to end of line.
Ctrl+B
Moves back one character.
Esc+B
Moves back one word.
Ctrl+F
Moves forward one character.
Esc+F
Moves forward one word.
Ctrl+D
Deletes a single character at the cursor.
Backspace
Deletes a single character.
Ctrl+R
Redisplays the command prompt and command line.
Ctrl+U
Erases a line.
Ctrl+W
Erases a word.
Ctrl+Z
Ends Configuration mode and returns to EXEC.
tab
Finishes typing a command for you.

Router Command History
Command
Meaning
Ctrl+P or Up arrow
Shows last command entered.
Ctlr+N or Down arrow
Shows previous commands entered.
show history
Shows last 10 commands entered by default.
show terminal
Shows terminal configurations and history buffer size.
terminal history size [0-256]
Changes buffer size (max 256).
To see how long a router has been up, how it was restarted, the IOS version, number of Interfaces, memory, and config-register setting use the command show version from privileged EXEC mode