IOS Upgradation- 7200 Series Router

Unanswered Question
Mar 17th, 2009

Hi, I am trying to Upgrage IOS of 7206VXR router. The size of image is 40 MB and I have only 24 MB free in Slot2. Can I erase the current IOS in running phase and trasfer the new One. If I delete the current live IOS, Would my router go in Rommon mode?? Please suggest.

I have this problem too.
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rpfinneran Tue, 03/17/2009 - 23:10

No, it wont go in rommon. When the router boots up it loads the IOS to NVRAM, so you can delete it from flash and add the new IOS.

However, it is better to try and keep both IOS's if possible by adding flash. If you delete the old IOS and the new one is corrupt, then the router will be in ROMMON. To help ensure this doesnt happen, after ftp'ing the new IOS, use the "verify /md5" command to make sure the checksum is good.

rpfinneran Wed, 03/18/2009 - 00:07

You could also try to install the new IOS and a corresponding boot image. The boot image is effectively a dumbed down version of the IOS, and allows some basic configurations to be loaded to the router. When the 7206 boots up, ROMMON is initialized. ROMMON then checks flash for a boot image. If one is found, the boot image will be loaded. The boot image would then load the full IOS from flash. However, if the full IOS fails, at least the boot image is running and should allow for basic IP connectivity, thus enabling you to download another IOS. HTH

Joseph W. Doherty Wed, 03/18/2009 - 12:17

Something else to be aware of.

If I remember correctly, the flash on a later 7200s IOS flash can be formatted one of two ways. The newer method supports dynamic reclaimation of space freed with file deletions. The older method either required lost space to be recovered by erasing the whole flash or "squeezing" it.

It's likely your 7206VXR is using the newer method, but if free space doesn't increase with file deletion, you might next try the squeeze command.

PS:

BTW: you can also format/erase/squeeze flash while the IOS is running on a 7200, but as the others have noted, until you have a good copy of the new IOS, you may have a problem on the next reload.

Something else to consider, there are configuration commands that can select the sequence of which IOS to boot (and from which flash device). Depending on configuration, you may need to adjust these to reload correctly.

Leo Laohoo Wed, 03/18/2009 - 14:31

I don't recommend erasing the old IOS without considering redundancies.

Purchase a compact flash card (maximum 2Gb) from your nearest camera shop or office supplier. Format it on the 7206 router and copy the IOS into the new one.

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