Yup. Gotcha. So what's the best solution in this situation?

My current solution, putting the Central and the Receivers on a different subnet, doesn't work well because it prevents the Central from getting track details from the internet. Although that's currently the only drawback to this arrangement.

There doesn't appear to be an option in the Central's configuration screens that allows it to act as a Reciever-Server without ALSO being a DHCP server for those receivers. Unless I'm reading the screens wrong. Is there a way to do this?

Putting the Central into full-auto mode (getting its DHCP address from the Alcatel modem) is also not desirable because I want the Central to have a fixed IP address so that I can use my little Central Streamer applet with it (my applet doesn't have the ability to do a broadcast-search for the Central).

The Alcatel modem doesn't have an option to pre-assign DHCP addresses to specific devices, so I can't go that route.

Creating a separate always-on server computer just to be a proper full-featured DHCP server is not in the cards for me at the moment.

Something I haven't tried yet: Making the Alcatel's DHCP server and the Central's DHCP server hand out addresses in the same range. When first trying the setup, I had deliberately arranged it so that the two were in different ranges so they wouldn't clash. Maybe that was the root of my mistake?