Question:

a) A firewall will be classified according to which layer of the OSI model the protection is at. Using this classification, explain the different types of firewalls.

b) Why is a demilitarized zone (DMZ) used in a firewall configuration? Explain the most important characteristics of a DMZ.

c) Explain five different types of computer viruses. Show the most dangerous type and justify your choice.

d) Briefly explain the essential features Microsoft ISA Server. How does it works and how is it configured.

e) Describe why WEP is no longer secure for wireless networks nowadays. Give two techniques that will be used to overcome this problem.

f) Explian the following form of attacks and rate them in order of lowest to highest advantage gained by a cryptanalyst:

i. Known plaintext
ii. Chosen ciphertext
iii. Chosen plaintext