What is a firewall – the types and value of quality protection

Posted on 26th August 2021

Even if you are new to the Internet, you have heard of firewalls. It is one of the fundamental means of protection online. A physical firewall in a building won’t let the fire spread. A cyber-firewall won’t let the malicious digital agents enter your machine and spread over your network.

What is a firewall, and how it works

A firewall is a software that filters your traffic, both incoming and outgoing. It guards the entry points (ports) of the device you use to surf the Web. All the data packets are scrutinized by the firewall that has a robust library of threats and rules. It analyzes the traffic and either allows the data packets or blocks them.

Thus, firewalls catch viruses and other malware. They repel the hackers’ attacks and protect your environment from any unauthorized access. With the regular updates, firewalls always stay informed about all kinds of new threats. You yourself can allow or disallow access according to the domain names, protocols, IP addresses, or just keywords. This way, you ensure that only trusted “visitors” can enter your network.

Different types of firewalls

Speaking of the types of firewalls, we should pay attention to the different classifications. The firewalls can be grouped by installation or by filtering settings.

By installation:

• Software firewalls
• Hardware firewalls
• Cloud firewalls

By filtering:

• Packet-filtering firewalls
• Circuit-level gateways
• Stateful inspection firewalls
• Application-level gateways (proxy firewalls)
• Unified threat management (UTM) firewalls
• Next-generation firewalls (NGFW)

Now, let’s dive deeper.

Types of firewalls by installation

• Software firewalls, or host-based firewalls, are applications installed on your devices. Modern OS, both desktop and mobile, come with predefined firewalls. Users can also install extra software guardians. However, this type of firewall is suitable for individual use mostly. Network environments require more advanced solutions.

• Hardware firewalls are physical devices. Instead of installing them on every machine, you’ll need to position these devices, attach them with wires, and connect them to power sources. The installation process takes more time and effort, but it is the right solution for the business level. That’s why the network firewalls are hardware.
• Cloud-based firewalls are becoming more and more popular these days as businesses tend to switch online to achieve more flexibility and scalability. Thus, cloud firewalls become an integral part of such environments. Their primary advantage is the possibility to manage traffic much faster and easier.

Types of firewalls by filtering

• Packet-filtering firewalls check the data packets that pass through the router. It relates to the IP addresses, port numbers, and other details on the surface level. They can’t access and analyze the contents, but inspecting the available allows them to protect your devices from threats.
• Circuit-level gateways check the source of the data packets and nothing more. The source must be approved by the TCP handshake. However, even in the case of a successful TCP handshake, the data packet may include malicious elements. It’s better not to rely on such a solution only.
• Stateful inspection firewalls combine the features of the two above types. The firewall decides whether to allow any specific data packet. The decision depends on the admin’s rules and the previous history. The firewall will check how it treated the traffic coming from that connection before.
• Application-level gateways/proxy firewalls rely on the proxy server first. The traffic comes through it first. At that stage, the firewalls analyze the data packets in-depth. It is only when they match the required criteria the firewall can let them enter the system.
• A unified threat management firewall (UTM firewall) is a complex solution. First, it checks the surface-level details about the sender and the connection. Then, it enhances the functionality by additional elements. These are antivirus and intrusion prevention modules.
• Next-generation firewall (NGFW) is a common name. Such new powerful firewalls have the best functionality of all. Besides all the standard options, NGFW should prevent all kinds of intrusions, block threatening apps, and improve protection techniques continually.

Unfortunately, there isn’t a standard comprehensive definition of an NGFW firewall. However, if you choose a software guardian for your system, you will most likely deal with NGFW one. So, refer to the official specifications and get familiar with the capabilities of this particular solution.

If you are concerned about your safety online, you will surely apply a firewall. They should be the modern NGFW solutions. Also, you need to take care of both the device and the network. That’s why the combination of hardware and software firewalls is the default these days. However, it is not the only tool in your possession.

Using VPN as an additional security level protects you with its own firewall too. For instance, there is a popular VeePN provider. Besides masking your IP address and unblocking access to the resources, it can filter connections. Adjust the VPN work to allow or disallow specific ports, and VeePN will guard your Internet connection on any device and at any location.

 Conclusion

New firewall solutions enter the market daily. They offer more functionality, easier and more flexible configurations, and faster operation. There is always a choice and a possibility to protect yourself with the best solution. Or a combination of such.