Which Ports Are Open on the Network? - Exam Answer

A penetration tester has been tasked with reconnaissance to determine which ports are open on the network.

Which of the following tasks should be done FIRST? (Choose two.)

A.

Network scan

B.

Banner grab

C.

Tracert

D.

DHCP server check

E.

Brute-force attack.

AC.

The two tasks that a penetration tester should perform first to determine which ports are open on a network are:

A. Network scan: A network scan is the process of identifying active hosts, their IP addresses, and the services running on them. This process helps to identify which hosts are live and reachable, and which ports are open on them. Network scans can be performed using various tools like Nmap, Angry IP Scanner, and Zenmap.

B. Banner grab: Banner grabbing is the process of capturing information about the software and version running on a service, which is usually displayed in the banner message sent by the server when a connection is made. Banner grabbing can be performed manually using Telnet, or using automated tools like Netcat or Bannergrab.

The other options in the question are not appropriate for this task because:

C. Tracert: Tracert is used to identify the route taken by packets between a source and destination. It does not identify which ports are open on a network.

D. DHCP server check: A DHCP server check is used to identify if there is a DHCP server running on the network and to obtain IP address lease information. It does not identify which ports are open on a network.

E. Brute-force attack: A brute-force attack is an attempt to guess a password by systematically trying all possible combinations until the correct one is found. This is not appropriate for determining which ports are open on a network and is also illegal and unethical without proper authorization.

In summary, a network scan and banner grab should be the first tasks performed by a penetration tester to determine which ports are open on a network.