Problem: SSG5 (SSG 20) doesn’t upgrade via it’s usb port and reports error “USB flash is not existed. Please insert USB first!”
Solution: You need to use a usb flash drive/stick that is 4GB OR SMALLER! And formatted FAT (aka FAT16). FAT32 will probably work too (I haven’t tried).
If you are on the SSG’s console, you will see the following error if you attempt to use a usb flash device bigger than 4GB:
“Usb disk size is larger than 4G.Mount failed!”
When you use a 4GB or smaller usb flash disk, you will see success:
“usb device (usb) ready.”
Again, this is on the SSG’s console.
Then you can upgrade via usb (put the *unzipped* screenos image in the *root* directory of the FAT usb drive):
ssg5-> save soft from usb ssg5ssg126.96.36.199r21.0 to flash
SSG5/SSG20 is a legacy Netscreen ScreenOS firewall/router.