Infrastructure Security
A firewall is a hardware or software system designed to protect one network from another network. The various types of firewalls are covered in Table 4.
Table 4. Review of Firewall Types Firewall Type Description Packet filtering Uses lists to check the source/destination network address, source/destination port, and protocol. Circuit-level gateway Monitors at the Session layer of the OSI and checks relationships between hosts to ensure it is allowed traffic. Application-level gateway Known as a proxy, this device functions at the Application layer of the OSI. It has the most complex set of rules and can control access by user ID and policies. Stateful inspection Combination of all three of the other firewall types. A router is an ...
Get Security+ Training Guide now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
