7500: lost connection after changing to 0x2142

Unanswered Question
Jun 14th, 2007

Hi all,

I am working with a 7500 router via Serial Interface.

The first I did was formatting a different flash card from de original and I copied a new Ios with ftfp.

Later, I used 'reload', answering 'yes' and

I realized with 'show version' that the first lines showed the new image version, but not the following, so while searching for information I found I had to change the register and I changed (wrongly) to 0x2142.

Just from that moment I lost the connection (minicom).

I am unable to establish again the communication.

I've tried with Ctrl+Break(standard and universal),and from both minicom and hyperterminal and also with and without flash cards inserted.

I would apreciate any help,

Alex.

I have this problem too.
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mahmoodmkl Thu, 06/14/2007 - 07:36

Hi

Try using different baud speeds until u get access to the console and check what exactly is going on there.

Thanks

Mahmood

alexkapi00 Thu, 06/14/2007 - 13:45

Thanks for your answer,

I have been yesterday trying differents speeds (with flash cards pluged)without result, and even this morning(now It's midnight).

I left the router powered without flash cards and I have just checked it before writing, and it is connected!

Now I can't get into privileged exec to change the register (hope 0x2102 be the solution)

PD:'show version' and possible commands attached.

Thanks.

Attachment: 
alexkapi00 Wed, 06/20/2007 - 01:57

Hi again,

Any idea on how returning to 0x2102?

I can't enable it from '>', because it says 'No password set'...

Thanks for any help,

Alex.

guruprasadr Wed, 06/20/2007 - 02:16

HI Alex, [PLS Rate if HELPS]

Attach a Terminal PC with Terminal Emulation to the console port of the router.

Use these terminal settings:

9600 baud rate

No parity

8 data bits

1 stop bit

No flow control

1. Press Break on the terminal keyboard within 60 seconds of power up in order to put the router into ROMMON.

2. Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash.

Note: This step bypasses the startup configuration where the passwords are stored.

3. Type reset at the rommon 2> prompt.

Note:The router reboots, but ignores the saved configuration

4. Type no after each setup question, or press Ctrl-C in order to skip the initial setup procedure.

5. Type enable at the Router> prompt.

You are in enable mode and should see the Router# prompt.

6. Type configure memory or copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.

Note: Do not type copy running-config startup-config or write. These commands erase your startup configuration.

7. Type show running-config.

The show running-config command shows the configuration of the router. In this configuration, the shutdown command appears under all interfaces, which indicates all interfaces are currently shut down. In addition, the passwords (enable password, enable secret, vty, console passwords) are in either an encrypted or unencrypted format. You can reuse unencrypted passwords. You must change encrypted passwords to a new password.

8. Type configure terminal.

The hostname(config)# prompt appears.

9. Type enable secret in order to change the enable secret password. For example:

hostname(config)#enable secret

10. Issue the no shutdown command on every interface that you use.

Note: If you issue a show ip interface brief command, every interface that you want to use should display up up.

11.Type config-register . Where configuration_register_setting is either the value you recorded in step 2 or 0x2102 . For example:

hostname(config)#config-register 0x2102

12. Type write memory or copy running-config startup-config in order to commit the changes.

FYI:TRY THIS: To reactivate the configuration file in NVRAM, enter configuration mode and reset the configuration register with the 'config-register' command. Set the 6th low-order bit (from the right) of the register to a binary 0. (You'll have to convert the final register value from binary to hexadecimal (0xABCD)for the 'config-register' command.)

PLS RATE if HELPS

Best Regards,

Guru Prasad R

alexkapi00 Thu, 06/21/2007 - 01:48

Hi, thanks for your info.

I've searching for the origin of the problem and I this is a summary:

- After copying the new image on the flash, I changed wrongly to 0x2142

- When reloading I answered 'yes', erasing information on nvram (startup).

Now:

- The only way to establish connection is without any flash card inserted.

- I can't use any break squence beacause 0x2142 ignores it.

- I think I've lost some commands when writing nvram on the reloading. Also, with 0x2142, it should read the startup configuration but I think it has been overwriten.

- I am stucked at 'Router(boot)>' with a few commands (attached before)and can't get into privileged exec because the password is not set.

I know it's a difficult situation due to my mistakes, but any help is welcome.

Alex.

guruprasadr Thu, 06/21/2007 - 02:15

HI Alex,

Can you try downgrade / upgrade of IOS with some external TFTP Server.

Pls Rate if Helps

Best Regards,

Guru Prasad R

smothuku Thu, 06/21/2007 - 02:40

Hi Alex ,

first do the password recovery using below procedure..

Press Break on the terminal keyboard within 60 seconds of power up in order to put the router into ROMMON.

Type confreg 0x2142 at the rommon 1> prompt in order to boot from Flash.

This step bypasses the startup configuration where the passwords are stored.

Type reset at the rommon 2> prompt.

The router reboots, but ignores the saved configuration.

Type no after each setup question, or press Ctrl-C in order to skip the initial setup procedure.

Type enable at the Router> prompt.

You are in enable mode and should see the Router# prompt.

Type configure memory or copy startup-config running-config in order to copy the nonvolatile RAM (NVRAM) into memory.

Important: Do not type copy running-config startup-config or write. These commands erase your startup configuration.

Type show running-config.

The show running-config command shows the configuration of the router. In this configuration, the shutdown command appears under all interfaces, which indicates all interfaces are currently shut down. In addition, the passwords (enable password, enable secret, vty, console passwords) are in either an encrypted or unencrypted format. You can reuse unencrypted passwords. You must change encrypted passwords to a new password.

Type configure terminal.

The hostname(config)# prompt appears.

Type enable secret in order to change the enable secret password. For example:

hostname(config)#enable secret cisco

Issue the no shutdown command on every interface that you use.

If you issue a show ip interface brief command, every interface that you want to use should display up up.

Type config-register . Where configuration_register_setting is either the value you recorded in step 2 or 0x2102 . For example:

hostname(config)#config-register 0x2102

Press Ctrl-z or end in order to leave the configuration mode.

The hostname# prompt appears.

Type write memory or copy running-config startup-config in order to commit the changes.

and

If the router is in boot mode, the router prompt may look like this:

Router(boot)>

If the router is in boot mode, you can proceed with the Cisco IOS software upgrade instructions below. Be careful not to save your configuration while in boot mode as the boot image does not contain full routing functionality.

Step 2: Verify that the TFTP server has IP connectivity to the router

Check the IP addresses of the TFTP server and the router targeted for the TFTP software upgrade to be sure the addresses are within the same range. Ping the router to verify that a network connection exists between them. To verify, check the IP address of the TFTP server. See Determining IP Addresses: Frequently Asked Questions for more details. If the router is in boot mode, you may need to set the default-gateway as follows:

Router(boot)>

Router(boot)> enable

Router(boot)# config terminal

Router(boot)(config)# ip default-gateway n.n.n.n-+

http://www.cisco.com/en/US/products/hw/routers/ps133/products_tech_note09186a0080094c07.shtml

Thanks,

Satish

mohammedmahmoud Thu, 06/21/2007 - 02:45

Hi,

Your only problem now is that you've lost your configuration, all that we have to do now, is that you should change the CR to 0x2102 and reconfigure your router and save the configuration.

HTH,

Mohammed Mahmoud.

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