1751 only boot to rommon

Answered Question
Jul 30th, 2007

i was upgrading a 1751 last night in my voicelab and when i reloaded the router after the new IOS was loaded into flash it boots to rommon>. i used the xmodem commands to load a different image and i removed an fxs card installed just before the upgrade. i changed the confreg back to 0x2102 and the baud rate back to 9600. i can see the image in flash with the dir flash: command.

i am stumped - i think i pressed yes when the router said " sys config has changed do you want to save" just before the first upgrade.

i almost forgot the error message during boot after the image decompresses

- *** Machine Check Exception ***

PC = 0x81432ebc, Vector = 0x200, SP = 0x800063dc

monitor: command "boot" aborted due to exception?

System Bootstrap, Version 12.2(1r)XE1, RELEASE SOFTWARE (fc1)

any information would be great.

thanks in advance.

Correct Answer by Edison Ortiz about 9 years 6 months ago

Basic IOS requires less memory. Voice features are memory intensive. If you plan on labbing with Voice stuff, purchase more memory.

I checked all available IOS images, even older ones and they all need 64MB DRAM for Voice support.

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jerry.mcrae Mon, 07/30/2007 - 08:05

looks like they say to reset confreg back to 0x142 and not 0x2102 or 0x2142. i'll test it later tonight.

thanks for the reply.

Edison Ortiz Mon, 07/30/2007 - 08:23

Confreg at x2102 should be fine. It seems the IOS is corrupted or there is a hardware installed on that router that is not supported under that IOS hence creating a bug check.

Can you fail back to the previous working IOS ?

Can you tell us what modules are installed on this router ?

jerry.mcrae Mon, 07/30/2007 - 08:35

Can you fail back to the previous working IOS ? no - i didnt pay attention to the IOS b/c it didnt support voice - yea i know lesson learned!

Can you tell us what modules are installed on this router ? wic-1dsu-t1 - i added a 2 port fxs before i restarted the router after the IOS copy to flash - i then removed the fxs after i couldnt escape from rommon. now i only have the wic card.

the router worked fine before i did the upgrade.

Edison Ortiz Mon, 07/30/2007 - 08:40

Can you try booting up the router without any module inserted in the chassis ?

Can you download a different release and try to xmodem again ?

jerry.mcrae Mon, 07/30/2007 - 09:02

yea i can try tonight after work. i'll post results tonight.

thanks for the help!!

EPHRAIM MANI Mon, 07/30/2007 - 23:33

a quick advice 1751 has an option of tftping at the rommon mode by using the command tftpdnld then setting the enironment it will be much faster load ios on to the flash.

Scondly i suspect teh IOS version is not appropriate/corrupt to the router hardware. Kindly provide the version of teh IOS u r going to install.

Kindly rate all teh post if it helps in anyway

jerry.mcrae Tue, 07/31/2007 - 07:40

i have never used tftp in rommon so ill check it out.

this is the version i want to use (c1700-ipvoice-mz.123-16a.bin). i want the 1751 to support a 2 port fxs for ccvp lab work (cvoice) and auto Qos if possible. an older image would be fine with me.

thanks for the reply. i have the router with me today so i can work on it after lunch.

mohammedmahmoud Tue, 07/31/2007 - 08:38

hi,

Please make sure that you router has got the appropriate memory/flash (64 / 16).

HTH,

Mohammed Mahmoud.

jerry.mcrae Tue, 07/31/2007 - 08:47

this router has 32/32 - will it need 64 to run the features i need (auto Qos, and fxs)?

Edison Ortiz Tue, 07/31/2007 - 09:38

32 DRAM is not enough and that's the reason it won't load. You need more memory.

jerry.mcrae Tue, 07/31/2007 - 09:42

not enough for voice support? it was working fine with a basic IOS.

so im trying to use the tftpdnld -r and i get this:

rommon 14 > set IP_ADDRESS: 10.10.250.1

usage: set

rommon 15 > set IP_SUBNET_MASK: 255.255.255.0

usage: set

rommon 16 > set DEFAULT_GATEWAY: 10.10.250.1

usage: set

rommon 17 > set TFTP_SERVER: 10.10.250.2

usage: set

rommon 18 > set TFTP_FILE: c1700-ipvoice-mz.123-16a.bin

usage: set

rommon 19 > tftpdnld -r

Missing or illegal ip address for variable IP_ADDRESS

Illegal IP address.

usage: tftpdnld [-r]

Use this command for disaster recovery only to recover an image via TFTP.

Monitor variables are used to set up parameters for the transfer.

(Syntax: "VARIABLE_NAME=value" and use "set" to show current variables.)

"ctrl-c" or "break" stops the transfer before flash erase begins.

The following variables are REQUIRED to be set for tftpdnld:

IP_ADDRESS: The IP address for this unit

IP_SUBNET_MASK: The subnet mask for this unit

DEFAULT_GATEWAY: The default gateway for this unit

TFTP_SERVER: The IP address of the server to fetch from

TFTP_FILE: The filename to fetch

The following variables are OPTIONAL:

TFTP_VERBOSE: Print setting. 0=quiet, 1=progress(default), 2=verbose

TFTP_RETRY_COUNT: Retry count for ARP and TFTP (default=7)

TFTP_TIMEOUT: Overall timeout of operation in seconds (default=7200)

TFTP_CHECKSUM: Perform checksum test on image, 0=no, 1=yes (default=1)

Command line options:

-r: do not write flash, load to DRAM only and launch image

rommon 20 >

what do you think?

ill get the basic IOS for a 1751 w 32/32.

Correct Answer
Edison Ortiz Tue, 07/31/2007 - 09:53

Basic IOS requires less memory. Voice features are memory intensive. If you plan on labbing with Voice stuff, purchase more memory.

I checked all available IOS images, even older ones and they all need 64MB DRAM for Voice support.

mohammedmahmoud Tue, 07/31/2007 - 09:46

Hi,

As Edison has pointed out, i've checked the IOS you are trying to use and it required min 64M of DRAM to successfully load the router, and thats why you face problems loading your router.

The DRAM/Flash required depends on the platform + the IOS loaded, when downloading an IOS please always make sure that your device has got the min required DRAM/Flash, and please note that some IOSs might require a min of 32M DRAM and others required 64M DRAM and so on.

HTH,

Mohammed Mahmoud.

jerry.mcrae Tue, 07/31/2007 - 09:53

As Edison has pointed out, i've checked the IOS you are trying to use and it required min 64M of DRAM to successfully load the router, and thats why you face problems loading your router.

OK im going to try this one c1700-y-mz.123-18.bin. i must have misunderstood the mem requirements when i downloaded. i will also order memory for the router.

i'll post the results after the new IOS.

thanks again.

mohammedmahmoud Tue, 07/31/2007 - 09:59

Hi,

Ok, the 12.3(18) requires also a min of 64 / 16, get your memory and enjoy your upgrade.

HTH,

Mohammed Mahmoud.

jerry.mcrae Tue, 07/31/2007 - 10:28

it worked!! i will get on that memory.

thanks to everyone who replied.

EPHRAIM MANI Tue, 07/31/2007 - 13:24

Another quick advice i suppose as suggested and as required DRAM is installed the router will come up automatically as the IOS is already in the FLASH, just while it is uncrushing that IOS in DRAM its not able to perform the same due to the deficiency of DRAM, so you will thru when you install additional DRAM and boot.

Thanks EM

Kindly rate all the post if it was informative.

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