Firewall - This Is how Your Network Is Protected | Antivirus Software

Definition and Functions of A Firewall

The firewall is essential for protecting your home network and the computers used on it. Here's how to protect your system from Internet threats, and our tips to find out if you're already protected by a firewall.

What Is it a Firewall?

A firewall is a computer program that protects individual computers or entire networks from unauthorized access. Literally translated, "firewall" means "firewall". The system protects your computer and your network from unauthorized access like a firewall protects the house from overarching fire.

The firewall is interposed between a public network (such as the World Wide Web) and your network (i.e. your devices connected to the Internet ). Every access and every incoming and outgoing connection is controlled by the firewall and blocked in the event of danger. If the connection is not dangerous, the firewall opens the requested port.

Firewalls can be found on every computer and even in routers or smartphones. Depending on the type of firewall, this is either permanently implemented in the respective operating system or additionally installed and individually configurable.

Basically, a firewall makes sense for every device that is connected to a different network or the Internet. For the protection to be effective, the firewall software must be updated regularly. With each update, the manufacturers close known security gaps, as they do with antivirus programs, for example.  

Why Do I Need a Firewall?

The firewall takes on an important protective function for your network at home. The network consists of all devices that are connected to the Internet via your router via LAN or WLAN. You and your applications are protected from malware such as computer worms as well as from hacker attacks with spyware.

Anyone who surfs the Internet with their devices without a firewall runs the risk of infection with malware within a short time.

An anti-virus program alone cannot replace a firewall. Only the firewall can scan the data traffic within the network and check incoming and outgoing connections for suspicious activity.

How Does a Firewall Work?

A firewall works much like a doorman. Before the incoming data packet from the Internet is allowed to reach your computer, it is checked by the firewall. Only when there is no threat does the firewall open the corresponding port (input and output for networks) and allow the flow of data.

For the firewall to work in this way, it needs definitions of which programs are allowed to use which ports and which are not.

To control the data packets, standard firewalls work with so-called “packet filters”. These filters consist of different rules or rule sets. The packet filter is applied to every incoming or outgoing data packet. The disadvantage of these systems is that they are static and always apply the rules once programmed. So you don't learn.

Advanced firewalls work based on "stateful inspection". The packet filters are dynamic in this case. The firewall not only checks the packet itself but also whether the recipient is ready to accept this packet. In this case, the recipient can be an app on your computer or hardware such as a printer. If a receipt is confirmed, the firewall continues to monitor the data packets flowing through according to fixed rules.

The “proxy firewall” is an even more complex variant. These firewalls work based on what is known as “deep packet inspection”. Here not only the sender and recipient as well as the packages themselves are checked, but the contents of the data packages are also analyzed. What is also special about the proxy firewall is that the data packets are controlled at the level of the respective application. The packets remain in the check until the firewall gives its OK for forwarding.

Firewalls of company networks or large IT networks work with additional modules to increase security. These can be, for example, so-called “intrusion detection systems” (IDS) or “intrusion prevention systems” (IPS). Also, many secure connections are created over a Virtual Private Network (VPN). The firewall then controls the data packets before they arrive at the recipient from the VPN tunnel.

Where Can I Find the Firewall?

If you are using a Windows machine and Windows 7 or later, you will already be using a firewall. Because Windows equips its Windows A defender with its own firewall.

Otherwise, you will find firewalls as part of antivirus software, e.g. from Protegent360. If the firewall is installed on your computer, it is also known as a "personal firewall" or "desktop firewall".

Many routers also have their own firewalls, such as Fritzbox routers. If the router already has an integrated firewall, this has the advantage that you can fend off attacks one level further and protect your network. Firewalls in routers are also known as “hardware firewalls”.

Windows Computers: How To Check If Your Firewall Is Activated

If you are using a Windows computer, you can find the Firewall by first clicking on Control Panel.

Then click on "System & Security". There you will find “Windows Firewall”. Click the field. If the tick is green, the firewall is active.

Mac: Where Can I Find the Firewall?

Mac computers also have a firewall. To do this, navigate to "Security" in the settings. There click on the “Firewall” tab. It should be activated.

If you use a virus protection program with a firewall, e.g. Protegent360, you do not need an additional firewall.

Is Windows Defender a firewall?

A firewall is part of Microsoft Windows Defender. In Windows 10 you can find the firewall as described above.

What happens if I turn off my firewall?

To install new virus protection programs or to test some programs, it may be necessary to disable the onboard firewall on Windows or Mac computers.

However, always keep in mind that if you turn off the firewall, you will not be protected from harmful intruders during this time. Therefore, you should never turn off your firewall permanently, or only if a third-party firewall is replacing your Apple or Windows firewall.

Enable ports in the firewall - this is how you give targeted access to your network

Every computer has a certain number of ports. These are possible accesses to this computer network. The ports are numbered from 1 to 65,536. A connection between the client and a server is established via a port. Once the connection is established, data packets can be sent back and forth. Such a connection is created, for example, when you surf the Internet with your browser. A specific port is then reserved for the browser. The same applies to e-mails or your network printer.

For example, you can "enable" ports via your firewall. This can be useful, for example, to enable a game console such as the PS4 to connect to the Internet via your network or WLAN.

If there are devices in your home network, these can often allow port forwarding independently. This means that these devices can open or close ports independently.

The typical ports that should always be released are 993, 995 or 80 and 443. These ports allow you to surf the Internet or mail to send.

Is Windows Defender a firewall?

The Windows Defender is a free security solution from Microsoft. The Defender is a firewall and antivirus in one. Windows Defender is automatically preinstalled from Windows 10. The settings can be found in the “Control Panel”, “Windows Security” area.

Windows Defender has become a very powerful program that offers a high level of protection against Internet threats.

Comodo Firewall - securely control connections in your own network

The US manufacturer Comodo is known for its software and SSL certificates. The company also offers a free firewall with basic functions for Windows users. For example, the Comodo Firewall queries applications that want to access the Internet.

The full version currently costs just under 30 US dollars per year and was recognized as a top product by the independent tester av-test.org, among others.

The advantages of the Comodo Firewall consist in the simple installation and control.

Conclusion: Without a firewall, there are no secure connections in your own network

Anyone who surfs the Internet and connects their devices to the Internet should always use a firewall to ward off attacks. You should therefore always check whether your firewall is activated on the Mac or Windows computer. Alternatively, you should activate the firewall of your virus protection program. Also, make sure that the system is always up to date. Therefore, download pending updates as soon as possible. In this way, the system also detects current threats in your network as well as incoming and outgoing connections.