What are the basic types of firewalls?
There are two types of firewalls: 1. Network Level 2. Application Level They are not as different as you might think, and latest technologies are blurring the distinction to the point where it’s no longer clear if either one is “better” or “worse.” As always, you need to be careful to pick the type that meets your needs.
Conceptually, there are three types of firewalls: Packet Filtering Firewall Application-level Firewall Stateful Inspection Firewall Packet Filtering Firewalls generally make their decisions based on the header information in individual packets. This header information includes the source, destination addresses and ports of the packets. Application-level Firewalls generally are hosts running proxy servers, which permit no traffic directly between networks, and which perform logging and auditing of traffic passing through them. A proxy server is an application gateway or circuit-level gateway that runs on top of general operating system such as UNIX or Windows NT. It hides valuable data by requiring users to communicate with secure systems by mean of a proxy. A key drawback of this device is performance. Stateful Inspection Firewalls restrict access by screening data packets against defined access rules. They make access control decisions based on IP address and protocol. They also ‘insp
They are not as different as you might think, and latest technologies are blurring the distinction to the point where it’s no longer clear if either one is “better” or “worse.” As always, you need to be careful to pick the type that meets your needs. Which is which depends on what mechanisms the firewall uses to pass traffic from one security zone to another. The International Standards Organization (ISO) Open Systems Interconnect (OSI) model for networking defines seven layers, where each layer provides services that “higher-level” layers depend on. In order from the bottom, these layers are physical, data link, network, transport, session, presentation, application. The important thing to recognize is that the lower-level the forwarding mechanism, the less examination the firewall can perform. Generally speaking, lower-level firewalls are faster, but are easier to fool into doing the wrong thing.
Conceptually, there are three types of firewalls: • Network layer • Application layer • Hybrids They are not as different as you might think, and latest technologies are blurring the distinction to the point where it’s no longer clear if either one is “better” or “worse.” As always, you need to be careful to pick the type that meets your needs. Which is which depends on what mechanisms the firewall uses to pass traffic from one security zone to another. The International Standards Organization (ISO) Open Systems Interconnect (OSI) model for networking defines seven layers, where each layer provides services that “higher-level” layers depend on. In order from the bottom, these layers are physical, data link, network, transport, session, presentation, application. The important thing to recognize is that the lower-level the forwarding mechanism, the less examination the firewall can perform. Generally speaking, lower-level firewalls are faster, but are easier to fool into doing the
