Answer: DMZ(Demilitarized zone )
Explanation: DMZ(Demilitarized zone) is the network area that exposes the external-facing operations of an particular organization towards the non-reliable networks.It is in the form of large sub-network.
This is the type of networking layer that helps in securing the server by creating the barrier between the secure network and the exposed untrusted network area.Thus, according to the mentioned situation in the question to separate out the traffic from entering client computers DMZ must be used .