Netgear Unbrick Utility
nmrpflashuses Netgear's NMRP protocol to flash a new firmware image to a compatible device. It has been successfully used on a Netgear EX2700, EX6100v2, EX6120, EX6150v2, DNG3700v2, R6100, R6220, R7000, D7000, WNR3500, R6400 and R6800, R8000, R8500, WNDR3800, but is likely to be compatible with many other Netgear devices.
Usage: nmrpflash [OPTIONS...]
Options (-i, and -f or -c are mandatory): -a IP address to assign to target device -A IP address to assign to selected interface -B Blind mode (don't wait for response packets) -c Command to run before (or instead of) TFTP upload -f Firmware file -F Remote filename to use during TFTP upload -i Network interface directly connected to device -m MAC address of target device (xx:xx:xx:xx:xx:xx) -M Subnet mask to assign to target device -t Timeout (in milliseconds) for NMRP packets -T Time (seconds) to wait after successfull TFTP upload -p Port to use for TFTP upload -R Set device region (NA, WW, GR, PR, RU, BZ, IN, KO, JP) -v Be verbose -V Print version and exit -L List network interfaces -h Show this screen
Download the correct firmware image for your device. When downloading from the Netgear site, the firmware is usually contained in a
.zipfile - extract this first. The actual firmware file will have an extension such as
Now, using an Ethernet cable, connect your Netgear router to the computer that will run
nmrpflash. Use the LAN port, which is often colored blue on Netgear devices. If the router has multiple LAN ports, use the one labled
Next, you'll have to determine which network interface corresponds to the one connected to the Netgear router. All available interfaces can be listed using
# nmrpflash -L eth0 192.168.1.2 c0:de:fa:ce:01:23 eth2 0.0.0.0 ca:fe:ba:be:45:67 wifi0 10.0.10.138 de:ad:be:ef:89:ab
For the rest of this example, let's assume that your router is connected to
eth2, and that you want to flash a firmware image named
First of all, turn off the router. Then start
nmrpflashusing the following command:
# nmrpflash -i eth2 -f EX2700-V18.104.22.168.img Waiting for physical connection.
As soon as you see the
Waiting for physical connection.message, turn the router on. If all went well,
nmrpflashwill continue printing messages:
Advertising NMRP server on eth2 ... / Received configuration request from fe:ed:1b:ad:f0:0d Sending configuration: 10.164.183.252/24 Received upload request: filename 'firmware'. Uploading EX2700-V22.214.171.124.img ... Upload successful. Waiting for remote to respond. Received keep-alive request (11). Remote finished. Closing connection. Reboot your device now.
Now reboot the device, and you're good to go.
In any case, run
-vvvbefore filing a bug report!
You must install your Linux distribution's
libnl-3packages (exact names will vary depending on your distribution).
On Debian based distros (such as Ubuntu) you can install these dependencies with
sudo apt install libpcap libnl-3
Install Npcap. For
nmrpflashversions prior to 0.9.14, install Npcap with "WinPcap Compatibility" enabled.
Version 0.9.13 was the last version to support Windows XP.
-> System Preferences -> Security & Privacy. Under the
Generaltab, there should be a message like "nmrpflash was blocked from use because it is not from an identified developer". Click the
Allow anywaybutton next to it, and run
If that doesn't work, try this.
Make sure the network interface is up (wireless interfaces are not supported). On Windows, try restarting the WinPcap service (commands must be run as administrator):
C:\> net stop npf C:\> net start npf
The router did not respond. Always run
nmrpflashin the sequence described above!
If that still doesn't work, you can try "blind mode", which can be invoked using
-B. Note that you also have to specify your router's mac address using
-m xx:xx:xx:xx:xx:xx. Also beware that in this mode, careful timing between running
nmrpflashand turning on the router may be required!
It's also possible that your device does not support the NMRP protocol.
The device did not respond to
nmrpflash's TFTP upload request. By default,
10.164.183.252to the target device, while adding
10.164.183.253to the network interface specified by the
-iflag. You can use
-ato change the IP address assigned to the target (e.g. if your network is
192.168.1.0/24, specify a free IP address, such as
-a 192.168.1.252), and
-Ato change the IP address used for the network interface.
After a successful file upload,
nmrpflashwaits for up to 5 minutes for an answer from your device. You can increase this by specifying a longer timeout using
-Tswitch (argument is in seconds).
It's entirely possible that the image was flashed successfully, but the operation took longer than 5 minutes.
nmrpflashrefuses to use an IP address / subnet mask combination that would make the remote device unreachable from the device running
nmrpflash. For example, if the IP address of your computer is 192.168.0.1/255.255.255.0, assigning 192.168.2.1/255.255.255.0 to the router makes no sense, because the TFTP upload will fail.
This can happen if the network interface in question automatically detects that the network cable has been connected, and your computer tries to reconfigure that interface (NetworkManager on Linux does this for example) - this can usually be disabled.
This usually means that flashing is in progress. On some devices, you may get a few hundred keep-alive requests before it eventually finishes!
By default, file transfers using TFTP are limited to
65535 * 512bytes (almost 32 MiB). Uploading files exceeding this limit might fail, depending on the device.
Extraneous upload requests are usually sent by the device if the image validation failed. Some possible causes are:
If you downloaded a firmware that's contained in an archive (a
.zipfor example), you must extract this file, and then use the contained firmware file as the argument to the
-fparameter. Some examples for file extensions used for firmware:
Some devices prevent you from downgrading the firmware. See if it works with the latest version available for your device. If you're already using the latest version, it might be possible to patch the version info of the firmware file. A future version of
nmrpflashmight incorporate an auto-patch feature for these cases.
Your device might expect a different image format for
nmrpflashthan when flashing via the web interface.
This could indicate that the device hasn't finished flashing, after the default timeout (5 minutes until version
0.9.4). Try increasing the timeout, using the
-Toption, for example use
-T 1800to specify a timeout of 30 minutes.
Specify the address of the router (
-a), and address of your computer (
-A). For example:
-A 10.0.0.2 -a 10.0.0.1
-A 192.168.1.2 -a 192.168.1.1
On Linux, developer packages for
libnlmust be installed:
$ sudo apt install libpcap-dev libnl-3-dev
Then, it's as easy as
$ make && sudo make install
On FreeBSD (assuming the ports infrastructure is installed and you have root permissions):
$ cd /usr/ports/sysutils/nmrpflash $ make install
Or install the FreeBSD binary package with:
$ pkg install nmrpflash
The repository includes a DevCpp project file (
nmrpflash.dev). Download the latest Npcap SDK and extract it into the root folder of the
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