You need to make the Virtual Machines able to talk only to each other.

You have external virtual switch with srv-io enabled with 10 Virtual Machines on it. You need to make the Virtual
Machines able to talk only to each other.

A.
remove the vswitch and recreate it as private.

B.
add new vswitch

C.
removevswitch and recreate it as public

D.
adjust srv-io settings

Explanation:
http://technet.microsoft.com/en-us/library/hh831823.aspx http://www.altaro.com/hyper-v/hyper-v-virtual-switchexplained-part-2/