What Is a Firewall and Why Do You Need One?

What is a Firewall?

A firewall is a hardware or software device that can be set up to restrict data from specific sites, programs, or ports while allowing relevant and necessary data to come through.

Firewalls block unauthorized access to or from networks with varying levels of trust. They prevent hostile actors from accessing private networks connected to the Internet by implementing security policies. A firewall can be set up using hardware, software, or a mix of the two.

Zero Trust policies can be used in conjunction with perimeter firewalls to ensure that network access is allowed appropriately and securely at every access layer of the OSI Model. Firewalls are sometimes dismissed as antiquated because they are created to secure a network's perimeter, but in truth, they are critical components of Zero Trust Architectures (ZTAs).

How does a firewall work?

A firewall is a network security solution that establishes a barrier between an external network and the network it is protecting. It's installed in the middle of a network connection and inspects all packets entering and exiting the protected network. As it examines packets, it uses a set of pre- configured criteria to distinguish between benign and malicious ones.

Data prepared for transmission over the Internet is called 'packets.' Data and metadata about the data, such as where it originated, are contained in packets. Firewalls can use this packet information to determine whether a given packet complies with the ruleset. If it doesn't, the packet will be denied access to the protected network.

Packet data can generate rule sets depending on various factors, such as the source, destination, and content.

At different network layers, these features may be expressed in different ways. A packet is reformatted numerous times as it travels through the network to notify the protocol where to deliver it. Various types of firewalls can read packets at different network levels.

What is the purpose of a firewall?

A firewall serves as a barrier between two networks. It detects and inhibits attempts to obtain access to your operating system, as well as unwanted traffic from unidentified sources.

How does it accomplish this? A firewall works as a barrier or filter between your computer and another network, such as the Internet. A firewall can be compared to a traffic controller. It manages network traffic to help safeguard your network and information. This involves blocking unsolicited incoming network traffic and authenticating access by scanning network traffic for unwanted content such as hackers and viruses.

A firewall is usually preinstalled with your operating system and security applications. It's a good idea to check if those options are enabled. Also, double-check your security settings to ensure they're set to install updates automatically.

Why do you need a firewall?

Now that you've learned what a firewall is, it should be obvious why you should have one installed and operational. But, just in case you're still not convinced, here are a few more reasons why you should use a firewall.

Prevent Unauthorized Remote Access with a Firewall

Someone attempting to take control of your computer remotely is one of the worst things that might happen to it. You don't want a remote intruder to seize control of your data and usurp your digital kingdom.

Remote desktop access should be disabled with a properly configured firewall (and a current operating system). This will prevent hackers from gaining unnoticed access to your machine.

However, this does not prevent the Windows tech support scammers from using remote control tools. These are browser-based scams that rely on you being duped into giving permission. You'll continue to be vulnerable to this danger because your browser already has permission to send data past the firewall. Maintain your vigilance!

Malware (Trojans, keyloggers, backdoors) is frequently preinstalled in illegal copies of Windows found on BitTorrent networks. You're likely to encounter security difficulties if you're operating one of these, even if you have a firewall setup.

Firewalls Can protect old PCs temporarily.

Even though Windows XP and Windows 7 were released in 2001 and 2009, respectively, people still use them. Worse, some of them are functioning without a firewall. Yes, you read that correctly. There is a lot of malicious code roaming the Internet, waiting to pounce on vulnerable computers. While your ISP can prevent this, its ability to intervene is restricted.

So, if you're a Windows 7 user (14 percent of computers as of June 2019), do yourself a favor and upgrade. To be safe, use a third-party firewall. After that, you can begin the upgrade procedure. If possible, upgrade to Windows 10 or even Linux.

Alternatively, you may get a new computer capable of running a modern, safe operating system because you're an easy, live target for hackers right now.

To keep your online gaming safe, use a firewall.

Online gaming is one of the most popular activities on the Internet, but it also poses a security risk. Various malware has been developed to target internet gamers that use game servers that are either insecure or have recently been compromised.

While most game publishers maintain their servers secure, a firewall is a good idea. Any efforts by hackers to get access to your system via malware will be denied, leaving your system safe.

The firewall will set things up according to the game's requirements, using metadata information in most circumstances. It's worth noting that many security suites come preinstalled with "Gaming Mode" or a similar feature. Before starting your favorite game, use this to optimize your computer and get the best performance possible. If you run into any issues, go to the game's support site and change the firewall application settings.

If you need to change some settings on your console, you can use hardware firewalls or routers.

A Firewall can be used to block inappropriate or immoral content.

So far, we've focused on preventing hackers and other sorts of remote access malware. Firewalls, on the other hand, are capable of far more. The option to restrict specific online destinations, such as adult websites, is generally included in firewall programs.

Content filtering is most commonly found in parental control software, but it's also becoming more common in firewalls. The ISP may manage content blocking in the United Kingdom and parts of the European Union. This is an opt-out service, which means you must notify your ISP if you want the block removed.

Hardware or software firewalls are available.

Firewalls do not have to be software, as previously stated. Most homes have hardware firewalls incorporated into their routers.

To access these firewall settings, you'll need the router's administrator credentials (make sure you've changed the default password). You should be able to review your options and make any necessary adjustments after you've signed in. You'll need to make some adjustments from time to time, especially if you're playing online with a games console. For example, on PlayStation 3 and PlayStation 4, changing the NAT type is a typical cure for online gaming connectivity troubles.

Before saving any changes, double-check the documentation for your router to acquaint yourself with the settings.

With that in mind, it's essential to think about what a firewall can't do. We've already described malware, including Trojans, viruses, worms, and other threats. While a firewall should prevent backdoor access with a Trojan, it's possible that this can be circumvented.

Worse, firewalls are powerless to stop viruses, worms, keyloggers, and other forms of malware. As a result, a firewall must be used in tandem with an antivirus program. The antiviral market is becoming increasingly tough to navigate these days. You'll need a list of the top security and antivirus software.