Update IOS on 2520 router

jmanning1979

I am having trouble updating IOS on my 2520 router via xmodem ( cant use tftp because I don't have transceiver). When I boot the router I see this:

System Bootstrap, Version 5.2(8a), RELEASE SOFTWARE
Copyright (c) 1986-1995 by cisco Systems
2500 processor with 6144 Kbytes of main memory
>?
$ Toggle cache state
B [filename] [TFTP Server IP address | TFTP Server Name]
Load and execute system image from ROM or from TFTP server
C [address] Continue execution [optional address]
D /S M L V Deposit value V of size S into location L with modifier M
E /S M L Examine location L with size S with modifier M
G [address] Begin execution
H Help for commands
I Initialize
K Stack trace
L [filename] [TFTP Server IP address | TFTP Server Name]
Load system image from ROM or from TFTP server, but do not
begin execution
O Show configuration register option settings
P Set the break point
S Single step next instruction
T function Test device (? for help)

IS this ROMMON mode? If not how do I get into rommon?

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Paul Boz

To get into rommon mode, reboot the router and press the break key within 60 seconds of booting up the router.

Here is the process for recovering IOS from rommon from Cisco's website. Do what I said to get into rommon (don't worry about changing the registry at this point) and pick up at the part about upgrading IOS.

http://www.cisco.com/en/US/products/hw/routers/ps233/products_tech_note09186a008009464c.shtml

jmanning1979

Doesn't work. I get a prompt that looks like this:

>

This prompt appears just a couple seconds after router switch is turned on.

mikej412

http://www.techexams.net/forums/viewtopic.php?t=22253
Yep, that's the Bootstrap Program, also known as the ROM Monitor.

The 2500 has the "limited IOS" in the bios that you can boot when your IOS on the flash is hosed. That may give you the XMODEM option.... or you can just do the XMODEM upgrade off the current IOS (and use the limited IOS in the bios as a backup plan in case you nuke the IOS on the FLASH).

The 2500 ROMMON mode does not do XMODEM or TFTP.... that I've ever seen. You can try the L option to "load from ROM"..... but I've never seen an example of that. Then maybe the I for Initialize. Oh -- or maybe just the B option.... B and return... and see what you get.

I tried the "B" on my 2511 terminal server and it just boot the IOS on the flash.

jmanning1979

xmodem command is not in limited IOS either. I do not have full IOS in flash, what are my options. Thanks.

mikej412

Do you have another 2500 router and a back-to-back serial cable? It looks like thats your best option until you get a transceiver -- TFTP over the serail cable from the IOS in the rom bios.

If you have a flash card.... I think there is an option to recover by opening the chassis and using the internal flash card slot.

I guess I should try the TFTP option in the 2500 ROMMON -- I always took the easy way when I was upgrading and never noticed the TFTP option no matter how many times I read the options

rossonieri#1

jmanning1979 wrote:

I am having trouble updating IOS on my 2520 router via xmodem ( cant use tftp because I don't have transceiver). When I boot the router I see this:

IS this ROMMON mode? If not how do I get into rommon?

in 2500 router -- yes, thats the ROMMON.

press I -- if you want to enter the basic configuration menu -- from there you can see how to update the IOS.

or O first -- if you want to see the config register.

cheers.