Firewalls Checkpoint

There are three main types of firewalls that operate on different levels of a network and accomplish the task of protecting the network in their own ways. Network level firewalls inspect packet headers and filter network traffic appropriately. Application level firewalls are also known as proxy services. These protect the network from malicious content by limiting the features, applications, and commands available to those on the network. Circuit level firewalls work within the session layer of the OSI. They determine the legitimacy of a requested session by monitoring the handshake making sure the process follows standard procedure. The circuit level firewall then can cloak a network from showing up to those who are trying to start a session illegitimately. Some of these methods, such as application level proxy services, take longer to examine information and could be seen as inefficient for this reason. When considering what method is most efficient I decided that I felt that a combination of the best features of all three firewalls was the most appropriate answer. This is known as a Stateful Multilayer gateway. Filtering is done at the network layer to determine legitimacy and evaluate of packet contents at the application layer - eliminating the use of slow proxy services and providing a direct connection between the host and the client.