DNS issue with UBNT devices

RouterOS General
1

I have several ubnt devices installed at customer end. These devices have DNS resolving issue with mikrotik. Using opendns as DNS servers. The issue is DNS proxy settings in ubnt devices. Sometimes enabling dns proxy works sometimes don’t. Sometimes disabling proxy settings works sometimes don’t.

This happens intermittently and cannot duplicate the issue to troubleshoot the same. Tried changing DNS settings in Mikrotik and other firewall/nat rules but no luck so far. We have other CPE at customer end and there we do not face such issue.

Hope someone must have faced this issue and have resolution to this.

2

On firmware version 5.5.2 the DNS proxy does not work when you are not running a DHCP server on the device.
Because there’s not “DNS Proxy” option on the web interface if the DHCP Server is disabled, you can fix it as follow:

  • Enable the DHCP server on the AirOS device with “DNS Proxy” enabled as well.
  • After rebooting/applying the DNS proxy service will run.
  • Simply disable the DHCP server, and Apply/Reboot.
  • The DNS proxy will stay active.