The TP-Link WR-703N is a nice, hackable pocket WiFi router. I’ve seen them put to some interesting purposes, but I didn’t own one until yesterday when the kind folk at QCon Shanghai gave me one. I’m not a fan of factory TP-Link firmware at the best of times, but more so when it defaults to Chinese, so it was time for another OpenWRT install (like I’ve done in the past with my TL-WR2543ND and TL-WR841N [1]).

First read the official OpenWRT Wiki article. The point of this post is to cover stuff that’s not presently covered in the Wiki.

I downloaded the stable Barrier Breaker release 14.07, r42625 factory update image and blundered through the Chinese language web UI to upload the new firmware and flash it.

By default the OpenWRT image comes up with no WiFi, and the ethernet port configured as LAN. This makes perfect sense from a security perspective, but not much sense for this particular device.

Turning on WiFi

Having connected to the ethernet port from my laptop I was able to access the web UI (and SSH). From there the WiFi can be set up by clicking on Network > WiFi.

Enable WiFi:

Provide a name for the network and make it part of the LAN:

Then turn on security and provide a key:

At this stage it’s time to connect to the WiFi interface – using the SSID and security key that were just configured. Unplug the ethernet cable to confirm that connectivity is still OK.

Ethernet == WAN

Next go to Network > Interfaces and Add new interface…

At this point the ethernet port (eth0) is on both the lan and wan, which isn’t good, so go back to the lan interface and edit out the eth0:

It should now be OK to plug the ethernet into a hotel outlet, your home network or whatever else you’re trying to WiFi enable with the mini router.

WiFi bridging (not working)

One of the things I love about WRTNode is the ability for it to route on from another WiFi access point, so with hotel WiFi you can sign in many devices but only need one registration. I’m told that it should be possible with the TL-WR703N, but I haven’t figured out how to do it. Putting in a similar block of config to what I use on WRTNode doesn’t seem to have the desired effect of creating an apcli0 device:

config wifi-iface
    ....
    option ApCliEnable '1'
    option ApCliSsid 'theSSID'
    option ApCliAuthMode 'WPA2PSK'
    option ApCliEncrypType 'AES'
    option ApCliPassWord 'theWiFiKey'

Note

[1] Both of these routers support the Barrier Breaker release 14.07, r42625 firmware, though the relevant Wiki articles haven’t been updated to reflect that.