Resolve Dynamic DNS to internal IP

I am not very familiar with dynamic DNS, and was curious if I could get it to work for a certain use case.

I have a few Raspberry Pi's I'm setting up for mocking server setups of applications we use at a small scale of our larger setup. They have wireless access capability. I'd like to be able to throw them in a bag and work with them using my laptop in various settings. However, working out the IP's and addresses every time to communicate with them on new networks would be quite annoying (having to change the endpoints all of the applications/configurations are referring to).

I can have normal DNS A Records point to internal IPs and they work great while on private networks. However this is less ideal for changing IPs. Would I be able to use Dynamic DNS to resolve the DNS records to internal addresses? (Such that connecting to a new wireless network all of the lookups would work after everything is connected without having to monkey with the router, custom dns server, etc.)

Initial research indicates Dynamic DNS usually resolves to the external IP whereas in this case I wish to automatically resolve to the address obtained on a specific interface for each client e.g. Eth0.

Answer

The simplest way forward would be to use mDNS to do "ad-hoc" DNS resolution amongst the machines in the same subnet. This is, basically, as simple as installing avahi-daemon and libnss-mdns (Debian package names; adjust as appropriate) and making sure your firewall isn't blocking 5353/udp. This will cover both forward and reverse DNS entries, and create resolvable names of the form .local for all other machines on the local subnet.

If you need naming which is available beyond the local multicast domain, you'll probably want to setup a DNS server somewhere on the Internet which accepts TSIG-authenticated UPDATE queries, and then configure your client machines to send updates using nsupdate (or some other equivalent means).