Clients discover the Apple Caching service bundled with macOS Server (and in the future macOS) automatically. You can create a text recored for _aaplcache._tcp on your DNS server. That would look
_aaplcache._tcp 518400 IN TXT “prs=192.168.50.100”
Name: _aaplcache._tcp with a type of TXT and a TTL of 518400 seconds. The prs is the address to be used and is set to a value using prs=192.168.50.100.
