What is the optimal placement for network-based intrusion detection systems (NIDSs)?

A.
On the network perimeter, to alert the network administrator of all suspicious traffic

B.
On network segments with business-critical systems (e.g., demilitarized zones (DMZs) and on certain intranet segments)

C.
At the network operations center (NOC)

D.
At an external service provider

Explanation:
A:Intrusion detection systems (IDS) monitor activity and send alerts when they detect suspicious traffic. There are two broad classifications of IDS: host-based IDS, which monitor activity on servers and workstations, and networkbased IDS, which monitor network activity. Page 750.