How to automatically register IIS service into DNS

I would like to have IIS service ruing with identical content on two Windows 2012 servers. Servers are only accessible from the intranet. The goal is that if service is ruing its name (FQDN) can be resolved by the DNS. So if both servers are up and ruing both IP addresses are served to clients. If service on one of the servers goes down the IP address of the impacted server should be removed from the DNS after the TTL expires. If the service comes back up it is entered to the DNS again automatically. Any ideas on how to achieve that? I've read that DDNS is the answer to this but I was unable to find any step-by-step instructions on how to implement it. Thanks F.