In this chapter, we discussed three types of firewalls: packet filter, stateful packet filter, and application proxy. a. At which layer of the Internet protocol stack does each of these firewalls...

In this chapter, we discussed three types of firewalls: packet filter, stateful packet filter, and application proxy.

a. At which layer of the Internet protocol stack does each of these firewalls operate?

b. What information is available to each of these firewalls?

c. Briefly discuss one practical attack on each of these firewalls.