subdomain.subsonic.org not resolving on internal network

[turnerrw]

I've been a subsonic user for years. Everything worked as expected until a couple/several years ago when my custom URL started failing to resolve to an internal address.

Now, I can use subdomain.subsonic.org externally, but I need to use servername:4040 when on my internal network.

Is this a feature that was removed from the product?

Do I need to make a server change (Ubuntu server)?

[G8DHE]

That is surely down to your local DNS resolving, possibly a change on the router or a server if you run a local DNS solution.

[turnerrw]

No local DNS; just my Verizon FIOS router.

[3Dscrewer]

No local DNS; just my Verizon FIOS router.

of course your Router is an DNS Server. If a Device is doing a request, the router is first searching in your local network and if not found the router is forwarding the request to the DNS Server of your ISP.
So if you cant reach subsonic by calling subdomain.subsonic.org your router don't know where to find. Since it works from outside, it is an internal problem.
First step is to look at the firewall, second step the router.

A workaround might be to edit the hosts file located in C:\Windows\System32\drivers\etc
you can add the local IP of the subsonic server and the domain name like that

192.xxx.xxx.xxx subdomain.subsonic.org (you need at least one space or a tab)