Small business firewalls come in four primary categories. Each category protects against a set level of the network. The four options include at the network, circuit, application or stateful multilayer level. Each level provides its own set of advantages and disadvantages for the small business.
A firewall protects a small business from a myriad of problems. Most importantly, it protects the network from hackers. Firewalls also protect the small business computers and devices against spam, viruses, Trojan horses and other harmful things that can happen if someone breaks into the network.
The most basic types of small business firewall protection is at the network level. This type of firewall checks access to the small business network by verifying information such as the IP address of the destination computer, the service requested and the port used to access the network. The firewall can also be configured to check for specific criteria prior to allowing access, such as specific domain names. This is the least expensive of the four options.
The circuit-level small business firewall works on allowing access to the network based on a three-step process. The first step of the process consists of one device sending a request to another device that is on the small business network. The second step is the device on the small business network then responds to the sending device. Once the original device acknowledges and validates the receipt of the information, then access to the network is granted. This option costs more than the network level firewall.
Application small business firewall options protect the network on an application level, such as software. For example, a small business that has a firewall for its email server provides protection against spam, viruses and other malicious attacks on the network, but only at the application level. The application firewall protection costs more than the two other options but less than the stateful multilayer level option.
The stateful multilayer level (SML) small business firewall offers the highest level of protection. This type of small business firewall combines the workings of all of the other three options into one comprehensive package. In addition, this type of firewall creates a direct connection between the host and the client. These types of firewalls also work faster than the other options. Because of the comprehensive nature of this type of firewall, however, it is also the highest priced of the four primary options.