Changed the firmware of my TP-Link TL-WDR3600 router from stock to OpenWRT then back to stock again

Recently, I have successfully changed the firmware of my TP-Link TL-WDR3600 router from stock to OpenWRT Attitude Adjustment (12.09 final). After some times, I decided to changed back the firmware to TP-Link stock Malaysia firmware version 3.13.32 Build 130723 Rel.9433n again.

The reason for me to make a move to OpenWRT firmware includes:

• There is no way to have an SSH terminal access to the router to gain more access and control to it.
• The 5GHz WiFi powered by stock firmware is auto-selected by my dual-band mobile devices within a short distance only. When the device is more than 5 meters from the router, it will auto-select the 2.4GHz WiFi instead.
• There is very little information and logging on real-time connections and bandwidth usage.
• The bandwidth control function is very basic, and lack of QoS functions.
• IPv6 is not supported by the Malaysian version of stock firmware yet.
• The stock firmware doesn't have VPN function. The router is unable to act as VPN server or connect to another VPN server as client.

It is pretty easy to convert the stock firmware of TP-Link TL-WDR3600 to OpenWRT Attitude Adjustment. The steps are as follow:

• Go to http://downloads.openwrt.org/attitude_adjustment/12.09/ar71xx/generic/ and download the OpenWRT firmware with SquashFS file system. If you select the firmware with JFFS2 file system, the steps below might not be applicable, and you might brick your router if you don't know what you are doing. The file to download for TP-Link TL-WDR3600 is: openwrt-ar71xx-generic-tl-wdr3600-v1-squashfs-factory.bin
• Backup current stock firmware settings by going to Backup & Restore and click the Backup button. If you haven't performed any backup to the firmware settings, you will need to manually configure back all the settings later if you decide to revert back to stock firmware.
• Do a factory reset to the existing stock firmware by going to System Tools > Factory Defaults and click the Restore button.
• Flash the downloaded OpenWRT firmware by going to Firmware Upgrade section of stock firmware and select the openwrt-ar71xx-generic-tl-wdr3600-v1-squashfs-factory.bin file just downloaded.
• When the firmware is successfully converted to OpenWRT, you can access its LuCI web interface by going to http://192.168.1.1 and login as "root" with no password.
• Before you do anything, perform a factory reset to the newly flashed OpenWRT firmware.
• To setup OpenWRT to work with TM Unifi, you can refer to this article here: http://klseet.com/index.php/tl-wr1043nd-ver18/setup-for-unifi-10031-rc6

With OpenWRT firmware, I am able to access the router with SSH. OpenWRT is modular, and you can add new function/feature by installing new packages in System > Software section. I have played around with monitoring tool, VPN, QoS, print server, DLNA server, and some other features.

However, I am unable to make its IPv6 to work, despite installing all the required IPv6 packages. It is either Unifi IPv6 is not implemented in my area yet, or I haven't managed to figure out how to configure IPv6 in OpenWRT to make it work.

With OpenWRT, I managed to configure the router to deliver a better 5GHz WiFi network with further reach. The 2.4GHz WiFi network is also able to stay in higher connection bandwidth with my mobile devices. However, I find that the WiFi configured by me on OpenWRT is not so stable, and after some times, some of my mobile devices are unable to establish connection with the router, unless I reboot the router and sometimes also need to reboot the mobile device.

After about 2 weeks of usage, I somehow concluded that the engineers at TP-Link have actually did a good job in tweaking and optimizing the firmware for this router, despite more improvement is needed in the area of WiFi, QoS, VPN support, and IPv6 for Malaysian version of firmware.

I decided to revert back to stock firmware due to the reason of:

• Only the stock firmware supports hardware NAT.
• It takes a few steps to configure something in OpenWRT, which can be easily configured in stock firmware with a single step.
• To gain back the stable WiFi, despite a weaker 5GHz range.
• To gain back the 2 years warranty of the router (just in case...)
• The stock firmware is already good enough for me.
• IPv6 is currently something good to have, but is not a must. Hopefully it will be included in future stock firmware upgrade.
• The physical switch behind the router to toggle WiFi on/off is only working with stock firmware.

The steps to convert the OpenWRT firmware in TP-Link TL-WDR3600 router to stock firmware is as follow:

• Download the version of stock firmware that is compatible to replace OpenWRT with ease here: http://www.tplink.com/resources/software/TL-WDR3600_V1_130129.zip. If you choose other version of stock firmware, it might not work, and you might brick your router if you don't know what you are doing.
• Unzip the file to get the stock firmware upgrade file wdr3600v1_en_3_13_26_up(130129).bin.
• Backup current OpenWRT firmware settings, just in case you want to use back OpenWRT again in the future. If you haven't performed any backup to the firmware settings, you will need to manually configure back all the settings later if you decide to return back to OpenWRT again.
• Do a factory reset to the OpenWRT firmware.
• Flash the TP-Link stock firmware wdr3600v1_en_3_13_26_up(130129).bin to the TL-WDR3600 router.
• Once you get back to the stock firmware, perform a factory reset again.
• You can now proceed to upgrade the stock firmware to its latest version. If you need the Malaysia version of firmware to support for Unifi or Maxis Home Fibre Internet, download the latest firmware from http://www.tp-link.com.my/support/download/?model=TL-WDR3600&version=V1.
• Restore the stock firmware settings from your backup that you have done earlier.
• If your Internet is not working yet after restoration, go to Quick Setup and run through the steps there. The VLAN settings should be properly restored now.