The firewall is a system that is used to protect a particular computer or a network. Normally its objective is to prevent the entry of external, unauthorized agents or information.
- Packet filtering firewall
- Circuit-level gateway
- Stateful inspection firewall
- Application-level gateway firewall
- Next-generation firewall
There are different Firewall types, which can be classified in different ways in:
Firewalls in Hardware or Software :
- Hardware: this type of system is placed on the devices used to enter the Internet, the so-called “routers”. Often the installation is already done when we buy the router. Otherwise, it is highly recommended to perform the installation. The placement of the firewall, in this case, is very complex, it is done thanks to a browser that has access to the Internet.
- Software: two types of these firewalls can be distinguished, the first is the free one: also known under the name of firewall software, which can be used freely and completely free of charge as its name indicates. Its purpose is to track and not allow access to certain data to personal computers. Nowadays most PCs already have the firewall in place.
This system is characterized by its easy installation, to which other systems can be added to ensure the computer when it stops working, it is the same PC that is in charge of notifying it, a Hardware system is not required to place it and they are generally used in a single computer.
On the other hand, there are commercials. These software systems have the same operation as the previous one. In addition, greater levels of control and protection are added. Many times they are sold with other security systems such as antivirus so that they are even more efficient in protecting the computer.
Another classification can be made according to your application or network level :
- Application: normally these are used with the servers called proxy. In this case, it is not possible to pass data directly between networks, since there is data monitoring. These systems are used to be able to translate certain network addresses, but always hiding the place where the traffic originates.
- Network: in this case decisions are made depending on the data ports, the destination address and the source of the information. To exemplify this class of firewalls, it could be a router, although it is already somewhat obsolete because there are firewalls that are more effective, especially when it is necessary to make a decision and also in terms of data. These turn out to be very fast and clear for the person who uses them.