How to TCP to a DNS hostname?

I have a website with dns setup where data is being sent to a hostname on the dns (data.example.com:8000). I'd like to capture that data (using a small go server), but every time I try to make a tcp conenction using net.Listen(), I get an error that the host does not exist. However, when I use a packet sniffer on that port, I can verify that it does exist and data is in fact being sent to it. Am I missing something here? I do web dev for the most part, so i'm not too familiar with TCP and networking, or if something else has to be setup to make the connection.