Network firewalls can be divided into software firewalls, which require a configured operating system, and hardware firewalls, which refer to a specific device designed to filter traffic, create a separate local area network (NAT) and act as a DNS or DHCP server and router. A hardware solution integrated with the VPN and used for user authentication. Hardware firewalls are relatively easy to install and configure. They also offer more predictable options and features.
In another classification, firewalls are divided into filtering firewalls and sharing firewalls.
Literally, firewall is a term that broadly defines the meaning of protecting networks, computers and systems from external attacks. The firewall is a form of network protection that monitors traffic entering and leaving the network. Most commonly used firewall blocks threats coming from the internet while using a wireless or fibre broadband connection. The firewall itself filters all packets according to certain rules, allowing or blocking their entry into the device. In which cases can a firewall prevent this?
Network traffic (the packets mentioned above) is blocked if the firewall detects suspicious activity such as viruses or hacker attacks. The firewall is therefore an important part of the computer and protects it from external attacks or dangerous software.
How does a firewall protect the computer?
Although the firewall monitors the outgoing traffic of the device, its main presence is the incoming traffic. The firewall carefully analyses individual packets and compares them with the filters and rules programmed to handle suspicious code. In the first case, for instance, if you want to activate a specific online game in Windows, you will receive a system request to add the title to the firewall’s exceptions. Otherwise, the firewall may block all traffic and prevent you from playing the game comfortably.
Packet filtering is one of the many methods used by firewalls, but it is more common in home devices (where a software firewall is used). The firewall is therefore the first line of defence and probably works better than other control software.
Types of firewall
I have already mentioned that there are software firewalls, but there is also a hardware firewall: what is the difference? The first is a programme installed on the computer (e.g. the Windows firewall), the second is an external device connected to a network and is a target device that only processes incoming and outgoing traffic from devices connected to it. Is it worth using both types of firewall to achieve 100 per cent protection?
Although this solution increases the security of devices, it is too cumbersome for home computers or laptops. For home use, a software firewall and discrete browsing is sufficient.
However, firewalls designed to filter packets are often too weak against the most sophisticated attacks and are often unsuitable for protecting sensitive objects. This is because they are limited by their inability to distinguish whether the content of a request for access to a particular application is false or not. Yes, such a firewall will detect a suspicious file, but cybercriminals can effectively conceal their activities so that the file can pass through the firewall and is only activated when it reaches its target (e.g. a system). However, some firewalls are better prepared to deal with such threats and can be divided into NGFW and proxy firewalls.
In companies that handle sensitive data, application firewalls are often used to analyse external traffic. These organisations are vulnerable to external and internal attacks. For this reason, various vendors (Fortinet, Sophos, Cisco) offer a wide range of network security solutions that include an application firewall.
They often describe their products as Next Generation Firewalls (NGFW).
These are highly sophisticated solutions that allow, for example, different types of protected phrases (secret or full document phrases) to be identified.
They then search for them in traffic generated by employees and scan them in real time. This prevents data leaks that are not intentional on the part of the employee. The traffic can be monitored almost independently of the transmission mode.
For example, the software can decrypt email attachments and identify images in the sent text or search for leaks in various document formats. It can also monitor some encrypted transmissions using a proxy method.
Another interesting feature is the learning mode, in which the device initially analyses only traffic generated by users and learns the specifics of their actions. This allows it to alert the administrator if, for example, an employee starts using their computer when the office is closed.
A medieval firewall known as a proxy server. This is a type of firewall that connects a specific computer to the network via a proxy. This type of broker closely monitors traffic, but has the disadvantage of limiting the bandwidth of the connection. However, a proxy firewall is sometimes called the most effective firewall.
When we talk about firewalls, we usually refer to solutions that can block traffic from specific IP addresses, protect services by blocking ports for external traffic, etc. Few people remember that so-called packet filtering is a basic feature found only in first-generation firewalls. The most common type of firewall today is the second generation firewall, the so-called stateful firewall. It extends what the first firewalls were able to do and can monitor the state of packets. This makes it possible to use the transmission state as a criterion for traffic filtering.
A firewall warning in Windows, usually triggered when a specific application (or game) tries to connect to the network for the first time. If it doesn’t work, it may not be working properly because the firewall is blocking it.
Yes, before Windows XP Service Pack 2 the default firewall had holes in it like Swiss cheese. It only took a few minutes to infect our devices with viruses online. Today, the latest versions of the system have a very powerful firewall, literally indistinguishable from standalone firewalls. Therefore, the firewall of the system is sufficient for home use.
But Windows Firewall is not loaded with additional features like other programs designed for it. Yes, they exist, but they can be difficult to use for inexperienced users. If you want better control over your firewall, you should invest in another firewall programme.