Solved: IOS Recovery by dialing in to Aux Port

syedraheel · ‎06-15-2011

We have Cisco 1811 and Cisco 2801 routers at each of our branch locations, Lets say its IOS gets corrupt. We have Aux ports and telephone lines plugged in for every router. Would I be able to use the Aux port and dial into it?(It would be in ROMMON Mode?) We have USB flash sticks also in every router. We wont have any IP connectivity from remote branch to the Head Office . The remote site engineer can only be of any "Physical help"

What would be the best procedure to restore the corrupted IOS image.

BR,

Arheel

Rozsa Illes · ‎06-15-2011

Hi Arheel,

You might consider connecting a modem to the console port. Here is a reference with advantages/disadvantages and configuration:

http://www.cisco.com/en/US/partner/tech/tk801/tk36/technologies_tech_note09186a008009428b.shtml#consoleport

For quick restoration, I would keep a flash (or USB) with a backup image or have a second image on the flash if you have enough space. It is possible to boot them from rommon like: boot flash:.

If it is not possible, we would have xmodem (very slow) or download via TFTP but both would be difficult if the onsite engineer has no knowledge of the procedure at all:

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

http://www.cisco.com/en/US/partner/products/hw/routers/ps259/products_tech_note09186a008015bf9e.shtml

Warm Regards,

Rose

View solution in original post

paolo bevilacqua · ‎06-15-2011

Rommon only uses console, not aux.

Don't worry too much. These are very stable devices.

Rozsa Illes · ‎06-15-2011

Hi Arheel,

You might consider connecting a modem to the console port. Here is a reference with advantages/disadvantages and configuration:

http://www.cisco.com/en/US/partner/tech/tk801/tk36/technologies_tech_note09186a008009428b.shtml#consoleport

For quick restoration, I would keep a flash (or USB) with a backup image or have a second image on the flash if you have enough space. It is possible to boot them from rommon like: boot flash:.

If it is not possible, we would have xmodem (very slow) or download via TFTP but both would be difficult if the onsite engineer has no knowledge of the procedure at all:

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

http://www.cisco.com/en/US/partner/products/hw/routers/ps259/products_tech_note09186a008015bf9e.shtml

Warm Regards,

Rose

syedraheel · ‎06-16-2011

Thank you

Can we define the boot device sequence like 1)flash 2)usb etc? so in case the IOS in flash is corrupt it boots from the USB image?

Rozsa Illes · ‎06-16-2011

Hi Arheel,

If you do not specify the boot statement, the router will try to boot the first file on the flash.

If you have multiple files, you can configure several boot statements. In this case the router will go one by one according to the order in the configuration.

Warm Regards,

Rose