Always disconnect all disks from your NSLU2 before starting the firmware upgrade procedure.

Below are instructions for installing the Unslung firmware, categorised by existing firmware version.

Note that when you install the Unslung firmware, you are completely replacing the previous firmware that was on the device. You are not adding Unslung to the existing firmware, you are replacing the existing firmware with Unslung.

Brand New NSLU2? Use The Linksys Interface

Use the RedBoot Upgrade mode if this does not work

If you wish to use Unslung to replace the factory firmware, then you can do so using the normal Linksys web interface. See the user manual that came with your NSLU2 for instructions on how to access this feature.

The best way to flash using the web interface is to remove everything from the Disk1 and Disk2 ports, then reboot the NSLU2, then flash immediately after boot without attaching any disks or attempting to do anything else.

Please note that a brand new NSLU2 doesn't use DHCP at all when booting, rather assuming that 192.168.1.77/8 is a properly working address. Them folks at Linksys are rather ignorantly assuming that their customers use their products (which all default to 192.168.1.0/8) and let them keep the factory default network settings.

Previous Unslung User? Use the RedBoot Upgrade Mode

It is recommended that all existing Unslung users use either Sercomm's Win32 tool or UpSlug2 to perform upgrades. See UseTheResetButtonToEnterUpgradeMode for instructions on how to enter the RedBoot Upgrade Mode.

Other Methods

There are also other alternatives you can use to install firmware without using the standard web interface or redboot upgrade mode, but they're much harder and unsupported.

See RecoverFromABadFlash for a step-by-step description on how to perform these other methods.