A firewall is a security protocol that protects your internal network from the threats of the internet. It keeps an eye on the data that comes in and out of your home network.
Without a firewall, your trusted private network could be at risk of cyberattacks, data breaches, and malware from the public.
The Technical Side of What a Firewall Does
To get to grips with how a firewall works, you need to understand how data travels between internet networks.
Basically, data moves across the internet in the form of information-filled packets. A firewall inspects these data packets to analyze their:
- Content: The information each data packet contains, such as an image, text, or video
- Protocol: The language of the data packet, for example, HTTP or TCP
- Port: The medium that the data is traveling through, such as email, web, or a social media network
- Source: Where the data is coming from, for example, the IP address or hostname of incoming traffic
- Destination: Where the data is headed, including the IP address, hostname, and other information that describes where the traffic is going
Afterwards, the firewall determines whether to let the data packet pass or, instead, to block it based on a set of predefined rules.
To ensure that dangerous data packets are blocked, it’s crucial that you create a solid set of rules for the firewall and update it regularly.
These firewalls come in the form of a physical device, like a router, that stands between a private network and the internet. Hardware firewalls offer robust protection, which makes them more useful for organizations and businesses.
Hardware firewalls are also often costlier than those installed on software. These types of firewalls, which are installed separately on lone devices, are also called host firewalls.
Fortunately, Windows and macOS come with in-built software firewalls that provide a basic level of protection against malware and hackers.
Keep in mind: Apple users need to turn on their firewalls manually, as it isn’t toggled on by default as is on Windows devices. Windows typically also offers better control and more in-depth data packet filtering compared to macOS.
For protecting various devices connected to the home network, personal firewalls are more useful. These are software firewalls installed on a network of devices rather than individual gadgets.
The Role a Firewall Plays in Protecting Your Home Network
1. Block unauthorized traffic
To reiterate, a firewall blocks threats coming from restricted sources or ports.
This means your firewall will block any data packets coming from a restricted IP address or website. It will also reduce your home network’s visibility to potentially risky protocols.
Firewalls can also block data packets that have malicious content.
Basically, firewall users can set predefined rules to give a firewall access control of their data. Based on these rules, the firewall will shut out intruders. For instance, parents may set rules in the firewall to deny access to certain applications or block out content based on certain keywords.
2. Defend against threats
A firewall serves as a checkpoint for all data packets, so it protects your home’s internet system from several threats, including:
- Cyberattacks coming from hackers who want to damage your system or steal and erase data
- Malware that infects not just software but also hardware, possibly destroying applications and devices
- Ransomware that locks important files, seeking funds from you to release it
Instead of just sniffing out these malicious invaders, a firewall neutralizes them in case they do enter your network. This way, it prevents the threats from spreading through your network infrastructure, further decreasing the scope of the damage.
3. Prevent application intrusion
Even if you expect untrusted applications to act out of line, sometimes your most-trusted apps will try to access and extract sensitive data from your device.
This can happen when the application is outdated, infected, or a hacker tries to use it to get into your system.
Thankfully, your firewall observes an application’s behavior to make sure there are no attempts to enter unauthorized resources. Doing so, it protects your sensitive data.
For example, if an application tries to access a location or photos on your device even though you haven’t allowed it to do so, the firewall will act immediately to stop it. Along with protecting your data, it will also inform you of unusual activity.
4. Improve network performance
Firewalls are more than security guards. Since they monitor the flow of traffic and keep an eye on who’s accessing your devices, they free up valuable resources. By doing so, they reduce network congestion and improve your performance online.
Apart from filtering out unnecessary traffic volume, a firewall also keeps the network’s functioning in check by increasing your security.
What’s more, firewalls prevent crashes that can occur due to cyber attacks, misconfiguration, or bugs in your system.
5. Maintain privacy
Imagine a stranger watching you through your window. Creepy, right?
This is something hackers may do to keep an eye on your data and browsing habits. They might even use your private information against you.
Here’s another area where a firewall is helpful. It shuts the curtains to such intruders to protect your privacy. A firewall also prevents software on your computer from sending out your personal information to prying eyes.
6. Log and audit data
Firewalls don’t merely observe the traffic coming in and out of the network. They also log lots of information about this traffic.
This data is critical in order to check the information later in case an unfortunate event arises and you need to go back and analyze what happened.
A firewall logs the timestamps, size, protocols, ports, IP addresses, and other details of a given packet. That gives it all the evidence necessary to investigate network activity.
For instance, if a bug enters your system and ends up disturbing it, you can access the firewall’s log to track exactly where it came from.
Apart from being useful in tracking activity, these logs are also helpful in identifying system or security issues in the long run.
7. Scan vulnerabilities
Some firewalls can also scan weaknesses in your network’s connected devices. This allows the firewall to alert you of outdated or misconfigured software.
They can also integrate with other vulnerability scanning programs to give you an idea of your network’s security position.
This isn’t all, though. Since firewalls can also analyze the severity of your vulnerabilities, you’ll be in a better place to prioritize important security upgrades or changes in the future.
What Doesn’t a Firewall Do?
While a firewall is an important part of a security system, it is still just a part. It’s far from the whole security powerhouse you’ll need.
For starters, you should still generate strong passwords and use antivirus software to protect your home network.
Plus, firewalls only inspect network traffic. Malware hiding within applications, files, or devices may go undetected. What’s more, skilled hackers can also slip through a firewall’s guard by using port hopping, spoofing, and other sneaky techniques to deliver malicious content.
All these tricks can fool the firewall into believing that a hacker is transferring legitimate data packets from trusted sources, ports, or protocols.
This isn’t all—other limitations of a firewall are listed below:
- It can sometimes act overenthusiastically and block legitimate traffic.
- It may sometimes fail to catch harmful traffic or take too long to alert you about trespassers.
- Misconfiguring a firewall can lead to gaps which leave a window open for cyber attackers to enter.
- Setting extremely restrictive rules can negatively impact user experience and cause poor firewall functioning.
Keeping these things in mind, it’s crucial to select a reputable firewall for your house, company, or personal website. Don’t forget to take additional security measures to protect your home network.
Some tools that can work along with a firewall to foolproof your security system include:
- Anti-phishing software: Blocks malicious websites, links, and content
- VPN: Encrypts and secures your connection by masking your online activity and covering your IP address
- Antivirus software: Defends against malicious software by scanning individual files, downloads, applications, and network traffic
- Intrusion detection system: Filters network traffic to protect against cyber hackers by blocking them before they can enter your system
Installing a firewall in combination with these solutions can protect you from online scams, attacks, malware, tracking, and sensitive data extraction.
Firewalls for businesses can also offer several of the above advantages all together in one package.
For instance, business firewalls come with intrusion protection and deep packet inspection. Some may provide a level of VPN functionality, too.
Owing to their deep packet inspection, such firewalls don’t just observe packet headers. They dive further in to check for malware and other threats hidden inside the data packet.
This doesn’t mean that businesses should forego additional security protocols. A layered approach to security is always a necessity. In short, the features and benefits of any single product will differ based on the type of firewall you choose.