Linksys NSLU2

This device is NOT RECOMMENDED for future use with OpenWrt due to low flash/ram.
DO NOT BUY DEVICES WITH 4MB FLASH / 32MB RAM if you intend to flash an up-to-date and secure OpenWrt version onto it! See 4/32 warning for details.

1) This device does not have sufficient resources (flash and/or RAM) to provide secure and reliable operation.
This means that even setting a password or changing simple network settings might not be possible any more, rendering the device effectively useless. See OpenWrt on 4/32 devices what you can do now.

2) OpenWrt support for this device has ended in 2022.
19.07.10 was the last official build for 4/32 devices.

The Linksys NSLU2 (a.k.a. SLUG) was a network attached storage device based on the IXP42x processor clocked at 133/266MHz. Is provided with a 2.0A 5V power supply.

NOTE: the support for NSLU2 was deleted along with the rest of IXP4xx from OpenWrt, but we are bringing it back as soon as OpenWrt is upgraded to kernel v5.19 or later using purely device tree and some rewritten and modernized device drivers. You can find preview images of kernel v6.1 and a working OpenWrt snapshot rootfs with LuCI and KSMBD on this webpage. The idea is to support only external hard disk or USB boot media as the internal flash is just 8 MB and will henceforth just contain the kernel.

Version/Model Launch Date S/N OpenWrt Version Supported Model Specific Notes
vx 2006-07 - Kamikaze 7.06 133MHz; can be easily “de-underclocked”
vy 2006-07 - Kamikaze 7.06 266MHz

Please check out the article flash.layout. It contains an example and a couple of explanations.

The NSLU2 at one point had an active user community around it at It was based upon Debian. Debian has since discontinued support for the NSLU2 in Debian 9 (Stretch) in June 2017. The developers at NSLU2Linux used to “bless” OpenWrt as the firmware of choice for people who want to run all their applications from the internal flash memory only (i.e. with no external storage at all). At one point there were several distributions available for the NSLU2; most contrast OpenWrt's minimalist philosophy. OpenWrt is for people who would rather spend their time adding the wanted features than deleting unwanted ones. As of writing (2019) OpenWrt is probably the only distribution still actively supporting NSLU2.

In case of problems, things to look out for are:

  • The default IP is the one that is set in the NVRAM, so OpenWrt will boot up with the IP it had under the former firmware. This is not the default for other Kamikaze platforms! Note: This is not true for Kamikaze SVN (tested with r8003). Note2: On upslugging the default IP of NSLU2 is (the same as the factory, Unslung and SlugOS behaviour) as of 08-2007. As of 8.09 RC1 the default IP is
  • Tip for dealing with 8.09 RC1 defaulting to . If your router uses the same IP address, you can use arp to let you connect to the NSLU2. For example, run “arp -s 00:04:5a:aa:bb:cc” (using your NSLU2s MAC address) on your client machine. Once you telnet to the NSLU2, edit /etc/config/network to change the IP, and run /sbin/reboot to restart the device, you can reset your arp table by running “arp -d”
  • After initial installation with the squashfs firmware, it can take up to five minutes to initialize the jffs2 payload partition. I would wait at least this time before you reboot it forcefully (although unplugging it while it is initializing didn't harm it in my tests)
  • The status LED indication differs from openslug. It is always amber for me (whereas openslug turns green after bootup is complete). This might confuse users migrating from openslug.

Set the NSLU2 into upgrade mode. To do this, make sure the NSLU2 is turned off. Then press the reset button with a paper clip or small screwdriver and keep it pressed. Turn the NSLU2 on. The “Ready/Status” led will be yellow. When it changes to a reddish amber shade, immediately release the reset button. If it flashes an alternating amber and green, you have succeded (if not, unplug and try again).

Now upslug2 should find the nslu2 over the LAN and display the information.

Install the image with upslug2 -d interface -i filename, for example:

  upslug2 -d enp7s0 -i openwrt-ixp4xx-nslu2-squashfs-factory.bin

It will flash and verify the upload and then reboot automatically. Example:

You can download the image from the OpenWrt 'Kamikaze' 7.06 dir Then install the upslug2 utility. Many distributions already include it in their package management (Fedora still ship it as of 2022). You will find more information on the topic on the excellect NSLU2-Linux wiki, specific information on upslug2 is at

The NSLU2 will take a few minutes to initialize the JFFS2 partition, don't reboot if you cannot access it immediately. It will start up using the network parameters that are stored in the NVRAM partition, so it will default to DHCP (I think) if not setup differently. If you have set a fixed IP address under the original firmware or a previous Linux distribution, OpenWrt will retain this. Try telnet and ping to access it. Then follow the standard Kamikaze installation procedures.

After flashing the device was reachable under

  • Installed OpenWrt 'Backfire' 10.03 on stock NSLU2 without any problems and works great. Added “option gateway” and “option dns” to “option ipaddr”, “option netmask”, and “option proto static” and kept the static setup with actual desired IP address. --- OddballHero 2011/01/31 12:57
  • I installed OpenWrt 'Backfire' 10.03.1-RC on my NSLU2, and it works just fine. --- Georg Sorst 2011/01/18 00:18
  • Installed OpenWrt 'Attitude Adjustment' 12.09, r36088 on my NSLU2. Worked like a charm ! --- MascH 2014/01/07 23:37
  • Installed OpenWrt Barrier Breaker 14.07 on my NSLU2. Works fine ! r0mulux 2014/10/30 20:53
  • Installed OpenWrt Chaos Calmer 15.05 on my NSLU2. Works OK ! xpact 2016/03/07 08:43

Since this part is identical for all devices, see Basic configuration.

To connect stuff to the USB port, please see Connect stuff to the USB port.

For Chaos Calmer you'll need to install the package:

kmod-usb2-pci and possibly kmod-usb-ohci-pci


For system that will interact with the other OS, it might be worth it to install samba3 instead of samba-server. Sample smb.conf for samba3 (please modify to fit your security needs and system requirements):

        netbios name = OpenWrt
        workgroup = WORKGROUP
        server string = NSLU2 OpenWrt Samba Server
        syslog = 10
        encrypt passwords = true
        passdb backend = smbpasswd
        obey pam restrictions = yes
        socket options = TCP_NODELAY
        unix charset = ISO-8859-1
        preferred master = yes
        os level = 20
        security = share
        guest account = root
        invalid users = guest
        smb passwd file = /etc/samba/smbpasswd

        comment = NSLU2 OpenWRT HD 1
        available = yes
        browseable = yes
        public = yes
        writeable = yes
        create mask = 0777
        path = /mnt/drive1
        read only = no
        guest ok = yes

Backfire 10.03 has most of the lights turned off (except for Ethernet) so use either the Luci web management (Administration→System→LED Configuration) feature (works quite well) or edit the /etc/config/system. GPIO Connections: has some information to help with the setup. Sample /etc/config/system entry:

config 'led'
      option 'name' 'GPIO2'
      option 'sysfs' 'nslu2:green:disk-2'
      option 'default' '1'
      option 'trigger' 'default-on'

Where additional choices for sysfs are 'nslu2:green:disk-1', 'nslu2:green:ready', and 'nslu2:red:status'.


  • Unplug the router's power cord.
  • Connect the router's LAN1 port directly to your PC.
  • Configure your PC with a static IP address: 192.168.1.x/24
  • Plug the power on and wait for the DMZ LED to light up.
  • While the DMZ LED is on immediately repeatedly press one of the buttons (Reset button or Secure Easy Setup button) until the DMZ LED will quickly flash 3 times every second.
  • You should be able to telnet to the router at now (no username and password)

The Linksys NSLU2 has one button. See nslu2.hardware.button for some options with that. - shut down via power button ( )

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  • Last modified: 2022/12/11 10:28
  • by linus