Thursday, November 10, 2011

Netgear WNDR3700

Received a refurbished Netgear WNDR3700 from TigerDirect today. The unit turned out to be a version 1, which was a bit of a bummer because v2 has a larger flash ROM. But no biggy, 8MB should still be big enough for DDWRT.

So I proceeded to install DDWRT, but things did not go smoothly. This step was problematic:

1a. Download DD-WRT for the WNDR3700 v1 from here depending on the region you purchased your router from: North America (NA):
That image left the router in a "boot loop". The only way to recover from that was the 45-second reset and then reinstall a factory image using tftp over a wire connection. Fortunately my old router was still working, so it was not difficult to download the factory image from Netgear.

I next installed OpenWRT, which went on smoothly. I was dismayed to discover that wireless was not installed by default, and that I would have to download packages and read documentation (I know, gasp) in order to figure it out. I wasn't in the mood for that, I just wanted plug and play, so I decided to try DDWRT again.

This time I followed the alternate instructions, which were to install the older 16785 revision and then upgrade to 17201 using the "webflash.bin" file. Fortunately this worked.

I had to install 16785 twice in order to get 17201 on it because after my initial success, I started to play around with some options. Somehow this left the 3700 in a completely useless state, so I had to start over again from the 45-second paperclip trick. The second time was a charm. The steps I followed were:

  • Reset the router using the 45-second paper clip trick. The power LED should blink green
  • Connect an ethernet cable to the router, configure the interface as static, and "tftp -i PUT wndr3700_factory_NA.img" (the 16785 revision).
  • Wait for the router to reboot, do the 30/30/30 trick to reset DDWRT to default configuration.
  • Browse over to, and upgrade to 17201 using the webflash.bin file.
  • Reboot, 30/30/30.
  • Configure DDWRT so the router to act only as an access point

That's pretty much it, aside from setting up the wireless security settings. So far so good, 29 days left in the 30 day warranty. If it dies, then I'll have something to take apart.