[stingraycharles]

Not necessarily. How would I go about making these IPs easily discoverable by other hosts? DNS again?

[teddyh]

Or mDNS: http://www.multicastdns.org/

As used by Apple’s Bonjour implementation of the Zeroconf networking stack.

If using Debian or the like, just apt install avahi-daemon and libnss-mdns, and access your hosts on the local network as servername.local.

[starfox64_]

Yes, you would probably then have to allow inbound traffic to these addresses in your ISP router's firewall or whatever you have.

If your router's default configuration is sane it should (by default) only allow returning connections and drop any other.