You notice that your FTP service reveals unnecessary information about your server. Which of the following is the most efficient solution to this problem?

A.
Filter out the login banner using a packet filter

B.
Disable the service in question

C.
Place the service behind the firewall

D.
Disable the login banner for the service

Explanation:
If the welcome message / login banner is a problem, then disable it.
Incorrect Answers:
A: The login banner is not a specific port or protocol that would allow a packet filter. If you applied the packet filter, then the FTP process won’t work at all.
B: Disable the service, which is FTP, and it is unusable. You will stop the disclosure of the information, but you can’t use FTP anymore.
C: Placing the service behind the firewall will not prevent disclosure of the information. The firewall will act like a packet filter, and can’t distinguish the banner from the data to be transferred.