Use a TP-Link TL-WR710N Router as a Repeater with OpenWRT

Although most Hotels I have recently been to offer free wifi, the connection is often barely usable or only works within one single sweet spot of the room where it is impossible to get work done. Especially when you are traveling having a working network connection is essential. As the available connectivity if often frustrating, I invested 20€ into a pocket wifi router which I would like to use as a range extender. I bought a TP-Link TL-WR710N as it is tiny and comes with a USB-Port. This is quite nice as as power plugs seem to be really expensive to build as most hotel rooms only offer a very limited amount.

router2

 

 

The  TL-WR710N offers five modes of operation:

  • Router mode
  • Client mode (connects ethernet devices to an existing wifi)
  • Repeater mode (extends existing wifis)
  • Access point mode (create a wifi hotspot from a wired connection)
  • WISP Client

Unfortunately the firmware which is installed on the device is very instable and barely usable for my purpose. I could not get connectivity by using the software which is pre-installed although it would offer a nice interface for all the mentioned modes.

Open source software to the rescue! Fortunately there exists a OpenWRT version which can be easily installed and which empowers this little device quite a bit. Have a look at the OpenWRT homepage and ensure that you have a supported hardware version (in Austria you will most likely get the EU 1.2 version with 8MB flash memory and 32MB RAM). You can use the upgrade dialog in the original firmware in order to upload the OpenWRT firmware. Be careful during these steps and avoid power outage and upload errors. Once you installed the new firmware, just follow these steps in order to setup a range extender with OpenWRT.

1) Connect your laptop with an Ethernet cable to the TL-WR710N router.

2) Establish a telnet session. The default IP is 192.168.1.1

telnet 192.168.1.1

There is no standard password.
3) For security reasons you should use a SSH session. To do so, you need to set a new root password by issuing the following command in the telnet session.

passwd

You will be prompted to enter the new root password twice. After you set the password, the SSH daemon becomes active and telnet gets disabled. Exit the telnet session with

exit

4) Connect via SSH by using the following command:

ssh root@192.168.1.1

5)
In the next step you need to configure the network interfaces. We want to have one Ethernet port eth1, one loopback device lo and of course the wireless interface wlan0.
Use the vi editor and open this file

vi /etc/config/network

6) Enter this interfaces into the opened file.

config interface 'wan'
        option ifname 'wlan0'
        option proto 'dhcp'

config interface 'loopback'
    option ifname 'lo'
    option proto 'static'
    option ipaddr '127.0.0.1'
    option netmask '255.0.0.0'

config interface 'lan'
    option ifname 'eth1'
    option force_link '1'
    option type 'bridge'
    option proto 'static'
    option ipaddr '192.168.1.1'
    option netmask '255.255.255.0'
    option ip6assign '60'

Save and close with :wq

7) Now we just need to configure the wireless connection. Use

vi /etc/config/wireless

to open the file.
8) Enter this wireless connection details below:

config wifi-iface
      option device radio0
      option network wan
      option mode sta
      option ssid 'WEAK-NETWORK-SSID'
      option encryption psk2
      # option encryption none
      # option encryption wep
      # option encryption psk
      # option encryption psk2
      option key 'PASSWORD'

config wifi-device  radio0
    option type     mac80211
    option channel  11
    option hwmode    11g
    option path    'platform/ar933x_wmac'
    option htmode    HT20
    # REMOVE THIS LINE TO ENABLE WIFI:
#    option disabled 1

# This is the bridged interface
config wifi-iface
    option device   radio0
    option network  lan
    option mode     ap
    option ssid     'REPEATED-WIFI'
    # option encryption none
    option encryption psk2
    option key 'mobileAP'

This wireless configuration contains the details how to connect and thereby extend an existing wireless network. In the configuration example above the name of this network is WEAK-NETWORK-SSID and the password for the PSK2 secured network is PASSWORD. Other encryption methods you could use are

              # option encryption none
              # option encryption wep
              # option encryption psk
              # option encryption psk2 

The second interface REPEATED-WIFI is your new, repeated wifi network where you then connect your laptop or your mobile phone with.

9) Reboot the router with this command

reboot

You should then see a second wifi with the name REPEATED-WIFI in the available networks list. As the small router still has a better range than some devices, you should have a nicer connection.

7 thoughts on “Use a TP-Link TL-WR710N Router as a Repeater with OpenWRT

  1. Hi,

    Nice article. I tried following your instructions, and am able to connect the router, but I keep getting a DNS_PROBE_FINISHED_BAD_CONFIG error when I try to connect to the internet.

    I read that sometimes these Atheros chipset has issues with bridged mode and that wds mode should be used instead. Has anyone else come across this issue?

  2. OK, as an update to my previous post. I found that there was something going funky with the DNS server. I was able to get my computer to work by specifying the dns server in the lan connection settings, but I believe there is a way to specify the DNS server using OPENWRT.

    http://wiki.openwrt.org/doc/uci/dhcp

    I haven’t tried it yet, but it looks like this will resolve the problem.

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