Which of the following tools would a security administrator use in order to identify all running services
throughout an organization?

A.
Architectural review

B.
Penetration test

C.
Port scanner

D.
Design review

Explanation:
Different services use different ports. When a service is enabled on a computer, a network port is opened
for that service. For example, enabling the HTTP service on a web server will open port 80 on the server.
By determining which ports are open on a remote server, we can determine which services are running
on that server.
A port scanner is a software application designed to probe a server or host for open ports. This is often
used by administrators to verify security policies of their networks and by attackers to identify running
services on a host with the view to compromise it.
A port scan or portscan can be defined as a process that sends client requests to a range of server port
addresses on a host, with the goal of finding an active port. While not a nefarious process in and of itself,
it is one used by hackers to probe target machine services with the aim of exploiting a known vulnerability
of that service. However the majority of uses of a port scan are not attacks and are simple probes to
determine services available on a remote machine.
Incorrect Answers:
A: An architectural review is a review of the network structure (servers, switches, routers, network
topology etc.). It does not list running services on computers.
B: Penetration testing evaluates an organization’s ability to protect its networks, applications, computers
and users from attempts to circumvent its security controls to gain unauthorized or privileged access to
protected assets. It is not used to list services running on computers.
D: A design review is the process of reviewing the design of something; examples include reviewing the
design of the network or the design of a software application. It is not used to list services running on
computers.
http://en.wikipedia.org/wiki/Port_scanner