disable opendns

If you removed them here...

Sys Prefs>Network, highlight the Interface you use, >Advanced>DNS tab, highlight the OpemDNS numbers & click the tiny minus icon.

Then check the DNS settings in your Router or Modem.

Router directions near bottom of page...

https://use.opendns.com

I use OpenDNS' numbers & Lcbo.com opened fine for me!?

Does this link show that you are using it?

click here to test your settings

Sys Prefs>Network, highlight the Interface you use, >Advanced>DNS tab, highlight the OpemDNS numbers & click the tiny minus icon.

Strange, never heard of OpenDNS being bad in any way... what are you seeing?

If the answer from BDAqua does not help it maybe the OpenDNS settings are being pushed to your broadband router from your ISP and then pushed by your router via DHCP to your Mac. Most ISP provided routers do not let you edit the settings to override this in the router but you would still be able to on your Mac edit the same DNS settings mentioned by BDAqua and this time add new ones.

As an example the Google DNS server addresses are 8.8.8.8 and 4.4.4.4

On your MacBook Air, go to System Preferences > Network > Wi-Fi > Advanced > DNS tab and post a screenshot of what you see.

Exactly where are you seeing these unwanted dns?