Firewalls are a crucial component of cybersecurity that works as a protective barrier between a computer network and the internet. It is a software or hardware-based security system that blocks unauthorized access to a network while allowing trusted data traffic to pass through.
Imagine your office has a security guard at the entrance to check visitors' identities before allowing them to enter. Similarly, a firewall acts as a gatekeeper for your computer network. It examines all incoming and outgoing traffic and decides which data packets are allowed to enter or leave the network.
How does a Firewall Work?
Firewalls prevent unauthorized access to your computer network by facilitating three essential security functions - packet filtering, stateful inspection, and proxy services.
1. Packet filtering
Packet filtering is the most basic form of firewall security. It involves examining the contents of the data packets and blocking them based on predefined rules. The rules are typically configured to block traffic based on protocol type (HTTP, FTP, POP3, etc.), source, or destination IP addresses, and port numbers. Firewall blocks packets that match the rules and allows the remaining packets to pass.
2. Stateful inspection
Stateful inspection, also known as dynamic filtering, is a more intelligent firewall security feature than packet filtering. Stateful firewalls track the state of packets as they travel through the network and analyze whether they are a part of an ongoing network connection. It considers both inbound and outbound traffic and allows only authorized data packets to pass.
3. Proxy Services
Proxy service is a more advanced firewall security feature. It acts as the middleman between your network and the internet, making it difficult for attackers to penetrate your network. When a user sends a request over the internet, the firewall intercepts and validates the request before forwarding it to the web server. It applies content filtering and URL filtering to control the user's access to the internet.
Types of Firewall
There are two primary types of firewalls based on how they operate - software and hardware firewalls.
1. Software Firewall
A software firewall runs on a computer as a software application and provides security to only that computer. It is a handy option for personal users who only need to secure their computer. They are easy to install and configure, making them an ideal choice for everyday use.
2. Hardware Firewall
A hardware firewall provides network-wide protection by filtering traffic at the network boundary. It is usually deployed as a dedicated device placed between the network and the internet. It is more secure and provides a broader range of features than software firewalls. However, it requires expert knowledge to configure and maintain, making it a better option for network administrators.
Benefits of Using a Firewall
Firewalls offer several benefits to individuals and organizations that use them. Some of the benefits are:
1. Protection against cyber-attacks
With the rise in cyberattacks, it is essential to secure your network from potential threats. Firewalls block malicious traffic and unauthorized access to your network, keeping your system secure.
2. Better visibility into network activity
Firewalls offer detailed insight into your network's traffic patterns, including source and destination IP addresses, protocol types, and port numbers. This information helps network administrators identify and control the types of traffic flowing in and out of the network.
3. Control incoming and outgoing traffic
Firewalls allow network administrators to create rules that block or allow specific types of traffic in and out of the network. It provides control over the types of traffic that are permitted to enter or leave the network, improving network security.
Real-life Examples of Firewalls in Action
Firewalls are in use all around us, secured behind the scenes to ensure that our daily activities go smoothly. Let us look at some common scenarios where firewalls come into play.
1. Online Banking
When you log into your online banking platform, the website's firewall checks your user credentials and authorized access to your account. Without a firewall, a hacker could potentially access your personal information and steal your funds.
2. Virtual Private Networks (VPNs)
VPNs create a secure connection between a remote worker's computer and the organization's network. Firewalls monitor and control the traffic flowing between the remote computer and the organization's network to prevent unauthorized access.
3. E-commerce
E-commerce websites store sensitive customer information, including credit card details, passwords, and home addresses. Firewalls protect this information from unauthorized access and prevent data breaches.
Conclusion
Firewalls are an essential component of cybersecurity that protect computer networks from unauthorized access, viruses, and other malicious traffic. They monitor and control traffic to ensure that only trusted data can enter or leave the network. By exploiting these benefits of firewalls, individuals and organizations can travel and work online with more peace of mind.
