The following are three types of security testing that are usually done by penetration testers:

• White box: White-box testing involves having complete knowledge – including network diagrams, IP addressing schemes, and other information – about the network and systems prior to the network penetration test. This type of test is much easier than gray-box and black-box testing since the penetration tester does not need to perform any sort of information gathering on the target network and systems.
• Gray box: In gray-box testing, the penetration tester is given limited knowledge about the organization's network infrastructure and systems prior to the network penetration test.
• Black box: In black-box testing, the penetration tester is given no prior knowledge about the target organization or its network and system information. The information that's provided about the target is usually just the organization's name.

Now that we have completed this introductory section to network penetration testing, let's dive into the essentials of understanding the MAC address.