When we talk about a network within a company, we often use a firewall to increase protection. But concretely, what is a corporate firewall? And what is it really for? Here is some essential information to be able to make the most of this type of device.
What is a corporate firewall?
A firewall or firewall is a security system used to protect a local network against threats from the external network. A company’s local network includes all the devices used by company personnel. These include computers, internal servers, printers and other peripherals useful for the smooth running of daily tasks. These different devices can contain sensitive data and an attack could compromise the proper functioning of the company.
The firewall then makes it possible to filter access to the local network from the outside. It acts as a barrier which only allows access authorized by the network administrator to pass. It thus helps prevent threats such as viruses, data theft or even the modification and deletion of company files.
The firewall is in the form of a device accompanied by software to be able to control it. However, in some cases it may consist of hardware or software only. In any case, the first option remains the most effective.
The administrator can configure the firewall by listing the devices that can access the company’s local network. In this case, all other access will be directly refused. Thus, only traffic known to the user can pass through their firewall. And even for authorized devices, we can still restrict access to certain elements of the network such as servers containing confidential data for example.
Les types de firewalls
All firewalls do not work in the same way and we can find several kinds.
Packet filtering firewalls
This type of firewall is currently the most common and works with IP addresses. Generally, the firewall analyzes the source and destination IP address of each packet. If each address matches the pre-established rules, access will be allowed. However, no information is available on the contents of the packets and the packets may therefore contain threats.
Application filtering firewalls
In addition to IP addresses, application filtering firewalls analyze the content of packets as well as what they want to do. Thanks to information about previously encountered packets, it will be possible to determine whether they are really safe. This type of filtering is then much more effective. The new generations of firewalls as well as multi-layered status inspection firewalls even allow a deeper analysis of the contents of the packets and not just their headers.
Intermediate firewalls
We can find firewalls à proxy who play the role of intermediary between the network and the outside world. The client’s request will then be analyzed by the firewall before obtaining or not an access authorization. There are also multi-layered status inspection firewalls which give a single address to the entire network. Thus, attacks targeted at particular devices will be much more difficult.
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