Rommon Problem 1720 IOS v12

[Guest_imported]

Hi,

I have two Cisco 1720s with two different problems I am hoping someone can help me with.
1. When I boot the router it keeps going into Rommon mode. How can I make it so it doesn't do that anymore?
2. Every time I configure this other 1720, then reboot it, the running config disapears and does not save to NVRAM.

Can anyone help?

Thanks,

Rmon.

 

[CCIEWANNABE]

A router going into ROMmon or boot mode could be caused by one of the following;
The configuration register (config-reg) is set like that
The dynamic RAM (DRAM) is bad
The router crashed and does not recover
The Cisco IOS® Software image is corrupted or not present.

Boot Failure Recovery Procedures can be viewed at this link:

http://www.cisco.com/warp/public/130/recovery_index.shtml

or

http://www.cisco.com/warp/public/130/recovery_c1700.html

Route once; switch many

 

[jeter]

1700 Series router Rom Monitor
How to enter Rom Monitor

Step 1. Enable
Step 2. conf t
Step 3. config-reg 0x0
Step 4. exit
Step 5. Reload

ROM Monitor
-? Displays a summary of all available ROM
reset or i Resets the router
dev Lists boot identification on the router
dir "device" Lists the file of the named device
b Boots the first image
b flash[file] Attempts to boot the image directly
b flash:2:[file] Attempts to boot the image second

Disaster Recovery with TFTP Download

rommon 1> tftpdnld -r (-r) optional
you should see a response

IP-ADDRESS:192.168.1.1
IP_SUBNET_MASK:255.255.255.0
DEFAULT_GATEWAY: 1.1.1.1
TFTP_SERVER:192.168.1.2
TFTP_FILE: c1700-???????-??.????

You will be prompt with
(Do you wish to continue? Y/N: [n]:yes

If all is correct the router will start to download the new image.

Ctrl-C or Break stops the transfer before the flash memory is erased.

rommon 7> confreg
save changes=YES
Reset or power cycle for the new image to take affect.
( reset ot i) to reset the router.

If all goes well be sure to check your config-reg is 0x2102

I hope this helps!

“Reserve your right to think, for even to think wrongly is better than not to think at all”

Fisher CCNA,(CCNP-Routing)
UOP Student BSIT

 

[Guest_imported]

Hi,

Thanks for the info. I tried the sugestions and non seemed to work. That or I am not doing it correctly. Here is what it says on then the router boots up.

device does not contain a valid magic number
boot: cannot open "flash:"
boot: cannot determine first file name on device "flash:"
Í
Any ideas? Or was teh sugested the rememdy?

Thanks,
Rmon

 

[gsears]

You've got a blown image.
The thing is booting to the baseline, "ROM" based OS, which is fairly stupid.

You need to format the builtin sram buffer and load a fresh copy of the OS, then the thing will take a configuration.

If you download a copy of the OS over the web,( filename FN) then run a TFTP host on that web-accessible machine, get its address (call it W1)

then, run the dynamic config to give the router an IP and netmask, (call it R1).

then,
copy tftp://W1/FN FN

That will copy it to your box.

How to format the machine's sram buffer, and how to activate the dynamic OS image, I have to read up on. Sorry.

 

[Guest_imported]

Thanks gsears, I will try this as well.
Rmon

 

[CiscoGod]

Dude I got a 1720 right here, I upgraded to 16MB Flash and it is doing the same thing. Here is how to fix it.

You need to have a tftp server available and a crossover cable to connect both. You will also need to have your cisco IOS image available from your tftp server software. (I use Pumpkin tftp server on my laptop. I change my ip address to 192.168.0.2 with a 255.255.255.0 sn mask.

You should be booting to a Rommon prompt>
type this:

IP_ADDRESS=192.168.0.1
IP_SUBNET_MASK=255.255.255.0
DEFAULT_GATEWAY=192.168.0.2
TFTP_SERVER=192.168.0.2
TFTP_FILE=???????????? (your image you download from CCO)

Type "set" to verify the above config
type "tftpdnld"
Then it will ask you if you want to erase the flash select yes and sit back.

after you are done type "confreg" and verify you are booting from 2 (boot flash) as opposed to rom mode.

You should be fine.

 

[jeter]

HHHMMMM looks very familier to what I posted. Did he ever resolve this issue? “Reserve your right to think, for even to think wrongly is better than not to think at all”

Fisher CCNA,(CCNP-Routing)

 

[TenSNut]

Thanks guys,

I got the other one to work but this one I am still stuck in rommon mode. I am going to attempt to fix this one now. I'll let you guys know the results.

Thanks again.
Rmon

 

[TenSNut]

It worked! Should have known that this was in a later chapter in my CCNA book. Thanks to everyone who helped!
Rmon