Commercial firewalls do not generally use the terminology packet filter, stateful packet filter, or application proxy. However, any firewall must be one of these three types, or a combination thereof....

Commercial firewalls do not generally use the terminology packet filter, stateful packet filter, or application proxy. However, any firewall must be one of these three types, or a combination thereof. Find information on a commercial firewall product and explain (using the terminology of this chapter) which type of firewall it really is.