cisco 2600 router confreg 1242

Answered Question
Aug 31st, 2012
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Hi everybody.

I have something to share with guys. I have been saving money to build my ccna voice lab. Recently I bought 2600 and 1700 series routers.

One of the 2600 router needed a password recovery so after a refreshing nap i got to work.


During the password recovery procedure, I mistyped confreg 0x1242; by the time I realized my mistake, my computer screen was full of "C" characters

Now the whole story is i can not console into it.


Is there any solution or should I start using my router as paper weight?


have a nice weekend.




Edit:


After some research, I found If I use the baud rate 1200 in hyperterminal.i will be able to console into it.

When I did that, I noticed that Rommon kept incrementing as:

rommon 1 >

rommon 1 > confreg 0x2142



rommon 2 >

rommon 2 >

rommon 2 >

rommon 2 >

rommon 2 > confreg 0x2142



rommon 3 >



thanks

Correct Answer by Reza Sharifi about 4 years 11 months ago

Hi Sarah,


In Rommon mode, the increase of  session number is normal. As Mahmood said, try "reset" at this point.


HTH

Correct Answer by Peter Paluch about 4 years 11 months ago

Hello Sarah,


The configuration register holds, among others, three bits that specify which speed should the console port operate at. These bits are protected in IOS, meaning that configuring the configuration register using the config-register global configuration command will never touch these three bits. However, in the ROMMON, this protection is not present, and the value specified by the confreg command will be directly stored into the configuration register. If it happens to touch the bits specifying the console port speed, you will immediately become unable to operate the router via the console until you configure your terminal software to the proper speed. This, however, becomes a guesswork if you change the configuration register value inadvertently - as you have experienced yourself.


The following document contains a table explaining the meaning of indvidual bits of the configuration register:


http://www.cisco.com/en/US/docs/routers/access/1800/1841/software/configuration/guide/b_creg.html


Best regards,

Peter

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mahmoodmkl Fri, 08/31/2012 - 19:53
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Hi,


From here just typr reset and see what happens.


Thanks

Correct Answer
Peter Paluch Fri, 08/31/2012 - 23:35
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  • Cisco Employee,

Hello Sarah,


The configuration register holds, among others, three bits that specify which speed should the console port operate at. These bits are protected in IOS, meaning that configuring the configuration register using the config-register global configuration command will never touch these three bits. However, in the ROMMON, this protection is not present, and the value specified by the confreg command will be directly stored into the configuration register. If it happens to touch the bits specifying the console port speed, you will immediately become unable to operate the router via the console until you configure your terminal software to the proper speed. This, however, becomes a guesswork if you change the configuration register value inadvertently - as you have experienced yourself.


The following document contains a table explaining the meaning of indvidual bits of the configuration register:


http://www.cisco.com/en/US/docs/routers/access/1800/1841/software/configuration/guide/b_creg.html


Best regards,

Peter

Correct Answer
Reza Sharifi Sat, 09/01/2012 - 06:58
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    2017 LAN

Hi Sarah,


In Rommon mode, the increase of  session number is normal. As Mahmood said, try "reset" at this point.


HTH

sarahr202 Sat, 09/01/2012 - 09:04
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Thanks Reza, Peter and mahmood


I finally got it working. The IOS file in flash somehow got corrupted which was the reason why i was getting increasing rommon mode like this:


rommon 1 >

rommon 1 > confreg 0x2142



rommon 2 >

rommon 2 >

rommon 2 >

rommon 2 >

rommon 2 > confreg 0x2142



rommon 3 >



Anyway, I found this link and used Xmodem protocol to transfer the image to flash.



http://www.cisco.com/en/US/products/hw/routers/ps259/products_tech_note09186a008015bfac.shtml#download_2620





Router#show flash


System flash directory:

File  Length   Name/status

  1   5248524  c2600-i-mz.122-5d.bin


thanks and have a great weekend

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