There are two levels of service discovery in DC/OS. Along with every task that runs on DC/OS being provided a well-known DNS name, anyone can request a well known VIP that enables clients to have a single configuration value.
You can assign a VIP or VIPs to one of your services by following the steps in the Service Discovery section.
Every task started by DC/OS gets a well-known DNS name. You can even enumerate every DNS name in your cluster. For a Marathon service named “testing”, you can find where it is running via:
Take a look at the mesos-DNS documentation for a more in-depth look at how Mesos-DNS is working and what it is doing for you.