I inherited some 2016 SQL Servers with an availability group and listener. The SQL instances are set up to use port 30001, and the AG listener is also set up to use port 30001. When I connect using the listener, I DO NOT have to specify the port--it just works. I know it shouldn't work, based on all the documentation. Can anyone tell me how this might be possible? In what scenario could you connect to a listener on a non-default port without having to specify the port?