I have been messing with an old Netgear WPM824V3 lying around. This WiFi router allows you to flash firmware through TFTP, which can be very useful when the Web interface is not available or when the flashed firmware doesn't work.
The procedure is quite simple and documented in this article. Other Netgear router models apparently have similar procedures to enter TFTP mode, so you can try it on your own Netgear router models.
Prepare Your Computer
Plug one end of an Ethernet cable into the Ethernet port of your computer, and plug the other end to one of the LAN ports on WPN824V3 router.
On your computer a TFTP client software must exist. I installed tftp-hpa package on my Linux Mint laptop.
$ sudo apt-get install tftp-hpa
Set WPN824V3 to TFTP Mode
- Unplug the power to WPN824V3, and wait for 15 secs to let current dissipate.
- Insert a paper clip into the reset hole to press and hold the reset button inside.
- Reconnect the power while keep holding down the reset button for about 30 secs.
- The power light at the front should become flashing and the check light should stay steady. That means WPN824V3 is now in TFTP mode.
Transfer the Firmware
Now you can transfer customized firmware onto WPN824V3. On my Linux Mint laptop I run this tftp command to send the firmware.
$ tftp 192.168.1.1 -m binary -c put firmware.img
Once the file transfer is finished, the power light should become steady along with the check light. Let the router sit for 2 mins with power connected. After 2 mins you should see the router automatically reboots, and it should be running the newly flashed firmware.
If your customized firmware doesn't work, just download an official firmware and flash it using the same procedure.