I’ve been having a terrible internet browsing experience for the last couple of weeks. Web pages would take up to 5 seconds or longer to load. Today, I finally had time to sit down and fully troubleshoot the issue.
I went to scrap Zentyal but then noticed that with the new firewall, there was no improvement. Turns out, Google DNS is at fault. Zentyal simply forwards DNS queries to whatever you tell it to. After changing DNS Forwarding (under DNS-> Forwarders) to my ISP DNS servers, web pages began loading instantly once again.
Hurray! Now time for another beer.