how to communicate vms in hyper-v from host machine

HI,

For some study and test purpose i installed 3 machines on hyper-v. one is for domain controller and in remaining 2 machines installed sql server. The all three machines communicates well among them. I want to ping the VMs from my host machine. Im using internal network adapter.

I want to add my host machine to domain controller and also i want to create shared folder. How can I achieve this, can any one please give suggestion.

Thanks!

KJ