Cisco 1720 issue

Answered Question
Jun 23rd, 2008

Hello,

I bought myself a CCNA kit containing 2 x 1720, 1 x catalyst, 1 x 2600.

I've managed to break one of the 1720s by altering a setting in the 'conf Memory'

Now, when ever it tries to boot up, I get

device does not contain a valid magic number

boot: cannot open "flash:"

boot: cannot determine first file name on device "flash:"

System Bootstrap, Version 12.0(3)T, RELEASE SOFTWARE (fc1)

Copyright (c) 1999 by cisco Systems, Inc.

C1700 platform with 49152 Kbytes of main memory

And prompts me with "rommon 2>"

monitor: command "reboot" not found

rommon 5 > ?

alias set and display aliases command

boot boot up an external process

break set/show/clear the breakpoint

confreg configuration register utility

cont continue executing a downloaded image

context display the context of a loaded image

cookie display contents of cookie PROM in hex

dev list the device table

dir list files in file system

dis display instruction stream

dnld serial download a program module

frame print out a selected stack frame

help monitor builtin command help

history monitor command history

meminfo main memory information

repeat repeat a monitor command

reset system reset

set display the monitor variables

stack produce a stack trace

sync write monitor environment to NVRAM

sysret print out info from last system return

tftpdnld tftp image download

unalias unset an alias

unset unset a monitor variable

xmodem x/ymodem image download

rommon 6 > reset

Does anyone know how I can fix this issue, or where I download the files to be able to re-image the router.

Hopefully then I can complete my course work ;O)

Thanks

Dave

I have this problem too.
0 votes
Correct Answer by DeonLouwBotha about 8 years 5 months ago

Hi Dave,

No problems in helping we all start and break things at some point :-)

To use the ROM monitor, you will be connected with a PC using the console port but this leaves the RJ45 ethernet port free on the router and PC for TFTP.

You will be using Console RJ45 (Router) -> Serial (PC) connectivity. If you are using an original cable it's a blue coloured cable with a RJ45 one end and a serial connector on the other.

Now connect a network cable to your PC and then the other end to the 10/100BASE-TX Fast Ethernet port (RJ-45) on the router. (Rommon should look on this port, there is however a note in one of the links I sent that a "10BASE-T Ethernet Port is not active in ROM monitor mode" there is however only 1 x 10/100BASE-TX ethernet port on the 1720's so I don't know exactly how this applies)

Set a static IP address and subnet on your PC (10.0.0.1, 255.255.0.0) use the "SET" command in ROMMON on the router to set the needed variables to get it working IP address (10.0.0.2), subnet (255.255.0.0), defaut gateway (10.0.0.1), TFTP Server (10.0.0.1), IOS Image (C1700-xx-xxx-xx.bin)

C1700-xx-xxx-xx.bin - replaces the xxxx with the relevant information.

Hope this helps and answers you questions

Deon

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hb21l6Cisco Mon, 06/23/2008 - 03:21

Hi,

I've tried this solution

http://www.cisco.com/en/US/products/hw/routers/ps359/products_tech_note09186a00800a750e.shtml

rommon 5 > confreg

Configuration Summary

enabled ar

load rom after netboot fails

console baud: 9600

boot: image specified by the boot system commands

or default to: cisco2-C1700

do you wish to change the configuration? y/n [n]: y

enable "diagnostic mode"? y/n [n]:

enable "use net in IP bcast address"? y/n [n]:

disable "load rom after netboot fails"? y/n [n]:

enable "use all zero broadcast"? y/n [n]:

enable "break/abort has effect"? y/n [n]:

enable "ignore system config info"? y/n [n]:

change console baud rate? y/n [n]:

change the boot character

enter to boot:

0 = ROM Monitor

1 = the boot helper image

2-15 = boot system

[2]: 2

Configuration Summary

enabled are:

load rom after netboot fails

console baud: 9600

boot: image specified by the boot system commands

or default to: cisco2-C1700

do you wish to change the configuration? y/n [n]:

rommon 6 > ?

But this doesnt work either.

Thanks

Dave

DeonLouwBotha Mon, 06/23/2008 - 04:11

Hi Dave,

Thats what I said in my first reply.

Post back if this doesn't solve your problem.

Deon Louw Botha

hb21l6Cisco Mon, 06/23/2008 - 04:17

Hi Deon Louw Botha

Thanks for the quick reply.

I don't have a new IOS, not sure where to get them from. I have found a document on this site that explains how to copy the image from another router, I was going to give this a try this evening.

Hopefully this will solve it.

Fingers crossed.

Dave

DeonLouwBotha Mon, 06/23/2008 - 05:00

Hi Dave,

If you have SmartNet and a CCO Login you can get IOS from Cisco.com click under support then download software then Cisco IOS Software.

Alternatively in your original post you said you had 2 routers both Cisco 1720's,

You can use the TFTP server (in other words the pc you have the TFTP software running on) to copy the IOS from one router to the other router if you don't have backups of IOS.

So the steps will be as follows to copy IOS from one to the other:

1. Install and configure the TFTP Server on a PC connected to your network, from your working Router ping the TFTP Server, if it fails then there is something wong, check that you have a default directory configured for the TFTP software etc. (get the TFTP Server working on the network)

2. Copy the working 1720 routers IOS to your TFTP Server, the IOS file is ussually something like c1700-**-**-****.bin and located in flash.

3. From your busted router in ROMMON use the set command to set the ROMMON variables (IP, Default Gateway, TFTP Server, etc) then use tftpdnld to get the IOS to copy from your TFTP Server.

You can try this TFTP Software it works well enough and its free:

http://www.solarwinds.com/products/freetools/free_tftp_server.aspx

The 1700 Series ROMMON guide

http://www.cisco.com/en/US/docs/routers/access/1700/1701/software/configuration/guide/rom_mon.html

How to copy from one device to another

http://www.cisco.com/en/US/products/hw/routers/ps233/products_tech_note09186a00800a6744.shtml

hb21l6Cisco Mon, 06/23/2008 - 05:22

Hi Deon Louw Botha

Many thanks for all the advice, I really appreciate it.

With my broken router not working, how will it see the tftp server on my PC? (no cat5e connectivity) can I transfer the image via the console cable?

Many thanks

Dave

Correct Answer
DeonLouwBotha Mon, 06/23/2008 - 06:03

Hi Dave,

No problems in helping we all start and break things at some point :-)

To use the ROM monitor, you will be connected with a PC using the console port but this leaves the RJ45 ethernet port free on the router and PC for TFTP.

You will be using Console RJ45 (Router) -> Serial (PC) connectivity. If you are using an original cable it's a blue coloured cable with a RJ45 one end and a serial connector on the other.

Now connect a network cable to your PC and then the other end to the 10/100BASE-TX Fast Ethernet port (RJ-45) on the router. (Rommon should look on this port, there is however a note in one of the links I sent that a "10BASE-T Ethernet Port is not active in ROM monitor mode" there is however only 1 x 10/100BASE-TX ethernet port on the 1720's so I don't know exactly how this applies)

Set a static IP address and subnet on your PC (10.0.0.1, 255.255.0.0) use the "SET" command in ROMMON on the router to set the needed variables to get it working IP address (10.0.0.2), subnet (255.255.0.0), defaut gateway (10.0.0.1), TFTP Server (10.0.0.1), IOS Image (C1700-xx-xxx-xx.bin)

C1700-xx-xxx-xx.bin - replaces the xxxx with the relevant information.

Hope this helps and answers you questions

Deon

hb21l6Cisco Mon, 06/23/2008 - 09:48

Hi,

I've just got home and I was going to take a copy of the image from the working unit. This one is also doing the exact same thing,

Now I'm really stuck until I can find an image. _ i'll have to have a look through my work places comms rooms to see if we've got any old 1700s laying around. thou I guess we won't

Is there any other way to fix these routers without having an image?

thanks in advance

Dave

hb21l6Cisco Mon, 06/23/2008 - 09:55

panic over..

After several reboots, it decided to load the image. I'm now taking an image of it.

Cheers

Dave

DeonLouwBotha Mon, 06/23/2008 - 22:35

Hi Dave,

Thats great news was just doing some research on an alternative method other than needing an IOS image when your update came through.

All the stuff that you just did is kind of part of your CCNA, so it wasn't a waste of time.

Glad your back on track, good luck with your studies and best of luck with your exam.

Deon

DeonLouwBotha Mon, 06/23/2008 - 04:06

Hi Dave,

Have you tried going into "0 = ROM Monitor" and uploading a new IOS from your TFTP server?

DeonLouwBotha Mon, 06/23/2008 - 03:27

Hi Dave,

The error you are getting is when an un-aligned write is performed to the device close to an internal 64-byte boundary. This has been seen only when writing a crash-dump file (written when the system is already crashing for some other reason). Normal writes to the bootflash (such as downloading a new image) and operations such as squeeze, erase, and so on have not shown this failure.

http://www.cisco.com/en/US/ts/fn/100/fn11211.html

Solution to this is via ROMMON update/upgrade/restore the IOS you can use the other 1720 you have via TFTP download the IOS to your TFTP server then use the tftpdnld command to TFTP the IOS onto the busted router.

This should sort out your problem.

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