> In that case you would do this kind of query (called SRV) for http.tcp. example.com You’re forgetting the underscores: It’s actually “_http._tcp.example.com”

> In that case you would do this kind of query (called SRV) for http.tcp. example.com You’re forgetting the underscores: It’s actually “_http._tcp.example.com”. The underscores are there to avoid any possibility of collisions with host names, since host names are not allowed to contain underscores, but are generally allowed in the DNS.