For Actiontec and ZyXel routers and most CenturyLink router/modems, there are two places for DNS settings.
1. Access the router's browser-based utility.
Log into your router’s browser-based utility by entering 192.168.0.1 or your default configuration IP into a browser.
3. Log into your router's configuration page
4. Ensure that WAN DNS settings are set to Obtain Automatically, and DHCP DNS is set to OpenDNS
To make OpenDNS work properly, please ensure that the setting for WAN DNS (first screenshot) is set to obtain dynamically, and configure the settings for the DHCP DNS (second screenshot) to 18.104.22.168 and 22.214.171.124. Then flush the DNS caches on the computer.
In rare cases, the WAN settings (the first set) may also need to be configured for OpenDNS as Static configuration for 126.96.36.199 and 188.8.131.52
5. Check your Settings