Security Strategies in Linux Platforms and Applications, 2nd Edition

CHAPTER
13	Testing and Reporting

ALTHOUGH YOU MAY TAKE every conceivable step to secure local systems and networks, that is not enough. Tests come in real time when attackers try to break through those security measures. Before an attacker can break in, you must test systems and networks for known security issues and measures.

Any test should apply to all parts of a layered defense, from an external firewall to the passwords selected by local users. You can monitor those ports that must be open to enable network communication. But if other ports are also open, attackers can use them to penetrate local systems without your knowledge. In this chapter, you will see what ports should be open and what you can do to keep unnecessary ports ...