Not reading the USB drive on the 4431 ISR

[KMNRuser]

We are having to upgrade our code on our router due to a published vulnerability.  What we typically do in this situation is burn the required image to a USB stick and then watch it when we put it in the router, and the router will give you back "Usbflash0: added" typically.

For some reason on the 4431 model we have inserted the USB stick with the file loaded on it, but we have no indication from the console output (after issuing a "term mon" on the SSH session we are monitoring the router with) that the USB stick was ever inserted.

 We tested it on a Cisco switch and it does see the USB stick added (it takes about a 10 second delay and then the console message appears).

I am trying to figure out if:

a) we are unable to use the USB slot on the 4431, and

b) the only way to get the image to the router is via TFTP or another secure file transfer protocol?

Thanks for any response(s)!

KMNRuser

[M02@rt37]

Hello @KMNRuser,

USB flash drive need to be a FAT file system, not FAT32.

You should use TFTP or SCP as secure transfer protocole.

[Richard Pidcock]

I've seen mixed results with various USB flash drives.  I would just try another flash drive.  Alternatively, you could run an SFTP server on your machine and connect directly to the device and then just SFTP the file over.  I do that quite often.

[Leo Laohoo]

Not all USB flash are supported with the router.  

For the routers, I find Toshiba-branded USB flash drive consistently compatible.  

[Elliot Dierksen]

In addition to the point made by M02@rt37 , try formatting the USB drive on the device being upgraded first. Then you can take it to a workstation and copy the file to it. It is an imprecise solution along the lines of "Nuke it from orbit, only way to be sure", but I have had success with it.

[Richard Pidcock]

Good call, and yes I've done the same and that will many times yield the needed results!

[KMNRuser]

Elliot,

Thanks for  your response.  I like the idea.  Let me give that a try and I will post out the results.

[KMNRuser]

Elliot,

Unfortunately i took a brand new USB and i did place it in one of the two USB slots on the 4431 chassis, but the box does not see it.  I even did a "sho file systems" command, but i do not see any usbflash0: in there..

[cweinhold · Accepted solution]

ISR routers only seem to support USB drives with 1GB or 2GB maximum sizes formatted for FAT. It does not support FAT32 used by larger USB drives. If you have a larger drive, you can plug it into windows and go to "Create and Format Hard Disk Partitions" in the control panel (aka FDISK), delete the existing FAT32 partitions, and create a simple 1 or 2 GB FAT partition.  Then the ISR router will recognize it.