I have three webservers in my home LAN (domotics, videosurveillance, Synology NAS). Right now, to access them from a remote client, I've set up a Dynamic DNS service and set the router (an Asus AC68U) to forward different ports to each local address.
What I would like to achieve, ideally, is a different subdomain for each web server so that I don't have to specify the port in the browser address bar. I.e., something like
nas.mydomainname.ddns.net redirecting to my NAS local address and so on.
As far as I understand, I can't use DNS SRV records for HTTP requests. What other options do I have? Is there something I could do with the ASUS router? Or could I use the Synology NAS to redirect the connections to the other two servers based on the subdomain name?