Our long running B20 suddenly started giving us the WAN failed DNS test. I have tried a few things to troubleshoot… I would appreciate any other things to try.
WAN1 = DSL (works fine)
WAN2 = Cable Company (problem child)
WAN3 = No connection (port is activated)
Connected a laptop directly to cable modem – I can get an IP and get on the internet
Ran different long from cable modem to WAN2, got WAN failed DNS test
Configured WAN3 with the WAN2 settings, cloned WAN2 MAC to WAN3 and moved the cable connection to it, WAN failed DNS test
Disabled Health Check – status is Connected but no internet activity
The mandatory router reboot (had to wait for this one)
This is happening suddenly to me too… I have a peplink balance 210 with firmware 7.1.2 build 3575. I created a support ticket #791191 a few weeks ago but no answer yet.