Modelo

Router password recovery is accomplished by rebooting the router and breaking into ROM monitor mode, setting the device to ignore the configuration file, rebooting, canceling the Initial Configuration Dialog, configuring memory, and then reading or resetting the password. You must be familiar with the password recovery steps for the test.

The following procedure is from Cisco’s web site. This is the procedure for routers using Reduced Instruction Set Computer (RISC)-based processors:

Step 1 Turn the power switch off and back on to recycle the power.

Step 2 Press the Break key or key sequence to put the router into ROM monitor mode. The Break key varies by computer or terminal software. The sequence

might be CTRL-D, CTRL-Break, CTRL-], or another combination.

configure memory

copy startup-config running-config

Copies the configuration in NVRAM into active memory (running configuration).

write memory

copy running-config startup-config

Copies the active configuration into NVRAM.

copy tftp running-config configure network

Copies the configuration file from a TFTP server into active memory.

copy running-config tftp write network

Copies the active configuration to a TFTP server.

write erase Erases the configuration file in NVRAM.

show configuration show startup-config

Copies the startup configuration in NVRAM to the terminal screen.

Example 3-11write erase Command Used to Erase the Startup Configuration

R1#write erase

Erasing the nvram filesystem will remove all files! Continue? [confirm]y

[OK]

Erase of nvram: complete R1#

R1#show configuration

%% Non-volatile configuration memory is not present R1#

Router Operations 81

Step 3 At the rommon > prompt, type confreg 0x2142 to boot from flash without loading the startup configuration in NVRAM at the next reload.

Step 4 Type reset. The router reboots but ignores the configuration in NVRAM. Step 5 The router runs the Setup Dialog. Type no or press Ctrl-C to skip the Initial

Setup Dialog.

Step 6 Type enable at the Router> prompt to go to privileged exec mode. Step 7 Copy the startup configuration to the running configuration by using the

configure memory or copy startup-config running-config commands. Do

not type configure terminal. If you use the configure terminal command, you overwrite the configuration stored in NVRAM.

Step 8 View the configuration by typing write terminal or show running-config. View the configured line, vty, and enable passwords. Any encrypted passwords need to be changed.

Step 9 Enter configuration mode by typing configure terminal. Change the line or enable passwords as necessary.

Step 10 All interfaces are in a shutdown state. Issue the no shutdown command on every interface that is to be used.

Step 11 Type config-register 0x2102 to return the router to normal operation at the next reload.

Step 12 Exit configuration mode by pressing Ctrl-z or End.

Step 13 Save your changes by typing write memory or copy running-config startup-config.

Step 14 Reload the router and verify the passwords.

The following is the procedure for non-RISC based routers. This procedure is from Cisco’s web site at www.cisco.com/warp/public/474/.

NOTE Non-RISC based routers include Cisco models 2000, 2500, 3000, 4000, 7000(RP), AGS,

and IGS.

Step 1 Turn the power switch off and back on to recycle the power.

Step 2 Press the Break key or key sequence to put the router into ROM Monitor mode. The Break key varies by computer or terminal software. The sequence

Step 3 At the > prompt, type o to record the current value of the configuration register (usually 0x2102, or 0x102):

>o

Configuration register = 0x2102 at last boot Bit# Configuration register option settings: 15 Diagnostic mode disabled

...

Step 4 Type o/r 0x2142 to tell the router to boot from flash without loading the configuration in NVRAM at the next reload.

Step 5 Type i to have the router reboot. The router ignores the configuration in NVRAM.

Step 6 The router runs the Setup Dialog. Type no or press Ctrl-C to skip the Initial Setup Dialog.

Step 7 Type enable at the Router> prompt to go to privileged exec mode. Step 8 Copy the startup configuration to the running configuration by using the

configure memory or copy startup-config running-config commands. Do

not type configure terminal. If you use the configure terminal command, you overwrite the configuration stored in NVRAM.

Step 9 View the configuration by typing write terminal or show running-config. View the configured line, vty, and enable passwords. Any encrypted passwords need to be changed.

Step 10 Enter configuration mode by typing configure terminal.Change the line or enable passwords as necessary.

Step 11 All interfaces are in a shutdown state. Issue the no shutdown command on every interface that is to be used.

Step 12 Type config-register 0x2102 to return the router to normal operation at the next reload.

Step 13 Exit configuration mode by pressing Ctrl-z.

Step 14 Save your changes by typing write memory or copy running-config startup-config.

Step 15 Reload the router and verify the passwords.

The index for password recovery procedures for all Cisco devices can be found at the following web site: www.cisco.com/warp/public/474/.

Router Operations 83