![icon](nmrpflash.svg) nmrpflash - Netgear Unbrick Utility ==================================== `nmrpflash` uses Netgear's [NMRP protocol](http://www.chubb.wattle.id.au/PeterChubb/nmrp.html) to flash a new firmware image to a compatible device. It has been successfully used with the Netgear D7000, DNG3700v2, EX2700, EX6100v2, EX6120, EX6150v2, R6020, R6080, R6100, R6220, R6400, R7000, R7000P R6800, R8000, R8000P, R8500, WNDR3800, WNDR4300, WNDR4500v3 WNR3500, but is likely to be compatible with many other Netgear devices as well. Prebuilt binaries for Linux, macOS and Windows are available [here](https://github.com/jclehner/nmrpflash/releases) ([Npcap](https://nmap.org/npcap/#download) is required on Windows). FreeBSD packages can be fetched and installed using the FreeBSD `pkg` command. ``` Usage: nmrpflash [OPTIONS...] Options (-i, and -f or -c are mandatory): -a IP address to assign to target device [10.164.183.253] -A IP address to assign to selected interface [10.164.183.252] -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 [255.255.255.0] -t Timeout (in milliseconds) for NMRP packets [10000 ms] -T Time (seconds) to wait after successfull TFTP upload [1800 s] -p Port to use for TFTP upload [69] -R Set device region (NA, WW, GR, PR, RU, BZ, IN, KO, JP) -S Skip bytes of the firmware file -v Be verbose -V Print version and exit -L List network interfaces -h Show this screen ``` ### Using nmrpflash Download the correct firmware image for your device. When downloading from the Netgear site, the firmware is usually contained in a `.zip` file - extract this first. The actual firmware file will have an extension such as `.chk`, `.bin`, `.trx` or `.img`. 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 `1`. 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 `EX2700-V1.0.1.8.img`. First of all, turn *off* the router. Then start `nmrpflash` using the following command: ``` # nmrpflash -i eth2 -f EX2700-V1.0.1.8.img Waiting for Ethernet connection (Ctrl-C to skip). ``` As soon as you see the `Waiting for Ethernet connection.` message, turn the router *on*. If all went well, `nmrpflash` will 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-V1.0.1.8.img ... OK (3539077 b) 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. ### Common issues **In any case, run `nmrpflash` with `-vvv` before filing a bug report!** ###### "Error while loading shared libraries: ..." (Linux) You must install your Linux distribution's `libpcap` and `libnl-3` packages (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 ###### "The program can't start because wpcap.dll is missing" (Windows) Install [Npcap](https://nmap.org/npcap/). For `nmrpflash` versions prior to 0.9.14, install Npcap with "WinPcap Compatibility" enabled. Version 0.9.13 was the last version to support Windows XP. ###### "nmrpflash cannot be opened because the developer cannot be verified." (macOS) Go to ` -> System Preferences -> Security & Privacy`. Under the `General` tab, there should be a message like "nmrpflash was blocked from use because it is not from an identified developer". Click the `Allow anyway` button next to it, and run `nmrpflash` again. If that doesn't work, try [this](https://support.apple.com/guide/mac-help/open-a-mac-app-from-an-unidentified-developer-mh40616/mac). ###### "No suitable network interfaces found." Make sure the network interface is up (wireless interfaces are not supported). On Windows, try restarting the Npcap service (commands must be run as administrator): ``` C:\> net stop npf C:\> net start npf ``` ###### "No response after 60 seconds. Bailing out." **Always run `nmrpflash` in the sequence described above!** You can try specifying the MAC address using `-m xx:xx:xx:xx:xx:xx`, or, if that still doesn't work, "blind mode" using `-B`. Note that careful timing between running `nmrpflash` and turning on the router may be required in this mode. It's also possible the bootloader itself is bricked, or that the particular device does not support the NMRP protocol. ###### "Timeout while waiting for ACK(0)/OACK." The device did not respond to `nmrpflash`'s TFTP upload request. By default, `nmrpflash` will assign `10.164.183.252` to the target device, while adding `10.164.183.253` to the network interface specified by the `-i` flag. You can use `-a` to 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 `-A` to change the IP address used for the network interface. ###### "Timeout while waiting for CLOSE_REQ." After a successful file upload, `nmrpflash` waits for up to 15 minutes for an answer from your device. You can increase this by specifying a longer timeout using `-T` switch (argument is in seconds). It's entirely possible that the image was flashed successfully, but the operation took longer than 15 minutes. ###### "Address X/Y cannot be used on interface Z." `nmrpflash` refuses 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. ###### "IP address of X has changed. Please assign a static IP to the interface." 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. ###### "Received keep-alive request." This usually means that flashing is in progress. On some devices, you may get a few hundred keep-alive requests before it eventually finishes! ###### "TFTP block rollover. Upload might fail!" By default, file transfers using TFTP are limited to `65535 * 512` bytes (almost 32 MiB). Uploading files exceeding this limit might fail, depending on the device. If it does fail, your only option is flashing an older image, which is smaller than 32 MiB. ###### "Ignoring extra upload request." 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 `.zip` for example), you must extract this file, and then use the contained firmware file as the argument to the `-f` parameter. Some examples for file extensions used for firmware: `.chk`, `.bin`, `.trx`, `.img`. * 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 `nmrpflash` might incorporate an auto-patch feature for these cases. * Your device might expect a different image format for `nmrpflash` than when flashing via the web interface. ###### "Timeout while waiting for 0000." after "Waiting for remote to respond." This could indicate that the device hasn't finished flashing, after the default timeout (15 minutes). Try increasing the timeout, using the `-T ` option, for example use `-T 1800` to specify a timeout of 30 minutes. ###### "bind: Cannot assign requested address" 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` or `-A 192.168.1.2 -a 192.168.1.1` ### Building and installing ###### Linux, Mac OS X, BSDs On Linux, developer packages for `libpcap`, `libnl` and `libnl-route` must be installed: ``` $ sudo apt install libpcap-dev libnl-3-dev libnl-route-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 ``` ###### Windows The repository includes a [CodeBlocks](https://www.codeblocks.org/) project file (`nmrpflash.cbp`). Download the latest [Npcap SDK](https://nmap.org/npcap/) and extract it into the a folder named `Npcap` in the source's root directory. ### Donate You can [buy me a coffee](https://www.buymeacoffee.com/jclehner) if you want, but please consider donating the money for charity instead - [Médecins Sans Frontiers](https://www.msf.org/donate) comes to mind, but any other organization, local or international, that you think deserves support will do. Thank you!