Archer C6 upgrades its firmware without asking the user, leading to bricked router
Hello TP Link community. I noticed a major potential problem with the Archer C6 v3.2 router by TP Link. And potentially with other routers as well.
When i tried to upgrade the firmware from the router's control panel (accessed via web browser) the router gave a message that the upgrade failed because the firmware file can not be downloaded from TP Link servers. Regardless of this message, at this moment there was internet and various web pages could be opened. Maybe there was a problem at the TP Link servers hosting the firmware file. I tried to upgrade several times during a period of half an hour, by clicking the upgrade button - and i always got the same message - the router can not upgrade itself because the firmware file can not be downloaded. So i decided that there was something wrong with the router - maybe it was crashed or somehow blocked, or it was frozen, since it was refusing to upgrade for half an hour. A restart may fix plenty of issues, so i decided to restart the router, to give it a fresh start. Then i thought, it should work properly and finally upgrade its firmware.
To my surprise, after that the router was bricked. Now all the lights on it were working, it was not possible to connect to it, there was no internet. Restart or factory reset did not change that.
Thanks to the instructions provided by TP Link, i managed to unbrick the router, after i connected it with a LAN cable to a computer and managed to install a firmware file manually.
So this experience uncovered a serious potential issue with the C6 router.
Apparently, after a failure to upgrade the firmware from TP Link servers, the router periodically keeps trying to upgrade it without notifying the user. You only get a message that upgrade failed because a firmware file could not be downloaded, but apparently the router silently keeps trying to download the firmware file and to upgrade itself without notifying the user. Meanwhile, the user is not aware of that and may do other things, without knowing that firmware upgrade is going to start at some point in the future (when the router is finally able to obtain its firmware file), and the user may interfere with that without knowing that a firmware upgrade is now in progress.
In my case, the user restarted the router without knowing that at some point later the router started to upgrade itself silently, without any message, with the "upgrade failed, can not download file" message still on screen.
To fix this serious potential issue, after the user clicks the upgrade button, the router should be made to only try to upgrade itself once, and if that fails - to display a message, "Upgrade failed. Firmware file can not be downloaded. Please try again later". Which gives to the user the information that the firmware upgrade process is over, and it will not resume by itself at some point in the future, and only if the user clicks the upgrade button again, then the router will try to upgrade its firmware again.
Please send this information to TP Link engineers, i'm sure that they will be interested in it and that a significant potential issue with this router (and maybe other TP Link routers) may be fixed that way. Thank you very much.