Question : What port does DNS use?

Our local network tends to have DNS problems.  I've never been able to figure them out, but anytime it happens I switch to using the DNS server my dedicated web server uses and it fixes it.  I've added that to forwarders on our DNS server here so that I wouldn't have to worry about it anymore.

Recently, I realized that my web server was completely open.  They didn't provide me with any router protection or firewall protection of any sort, therefore, I went ahead and enabled the Windows firewall on the server.  I opened up the email ports, web server ports, ftp, etc. and all of that is working fine.

Today, we began having DNS troubles again here on our local network.  I was able to browse the internet if I used IP addresses, and I could ping google's IP address, however, I could not ping any of the IPs associated with my web server.  Also, the fact that trying to use the web server's DNS wasn't working was confusing me considering the fact that I could remote desktop onto my web server and browse the internet perfectly fine.  I disabled the Windows Firewall and sure enough, our local internet started working again and I could ping my web server's IP addresses.

What do I need to open in the Windows Firewall so that I can leave it on and still use the DNS servers as I'd like to?

Any information would be greatly appreciated.  Thanks!

Answer : What port does DNS use?

DNS uses Port 53