What is a firewall?
A firewall is a network security device designed to monitor, filter, and block external threats. Its primary job is to act as a gatekeeper, deciding what traffic can enter or leave your device or trusted network based on predetermined security rules.
Firewalls sit at the entry point of your device or network, such as your home router or computer. They check small chunks of data against firewall rules. If the traffic matches the rules, the firewall lets it through. If the traffic looks suspicious or breaks the rules, the firewall blocks it.
Both individuals and organizations use firewalls to protect their networks from cyberattacks and other security risks. Without a firewall, companies can suffer massive financial losses and reputation-harming data leaks, so they’re a critical part of any comprehensive security protocol.
Types of firewalls
There are different types of firewalls that offer varying levels of inspection and protection.
- Hardware firewalls run on a dedicated physical device that sits between your network and the internet.
- Software firewalls are programs installed on devices that need protection.
- Cloud-based firewalls are delivered on demand over the internet by SaaS providers.
Different firewalls also operate in slightly different ways.
- Packet filtering firewalls look at the basic label on a data packet (such as its sender, destination, or connection type) to see if it can pass through.
- Application-level gateways (proxy firewalls) use a proxy server to conceal internal IPs while scanning client requests for potential threats. These firewalls are best suited to corporate networks handling sensitive information.
- Stateful inspection firewalls use a database of familiar packets to let known traffic pass through faster next time.
- Next-generation firewalls (NGFWs) supplement traditional firewalls with advanced cybersecurity features, such as malware blocking and intrusion prevention. The next step is to use AI and machine learning (ML) technology to proactively detect potential threats to private networks.
Firewalls don’t encrypt data — they only track and filter traffic according to firewall rules. They also can’t keep your data safe on untrusted external networks or public Wi-Fi.
What is a virtual private network (VPN)?
A virtual private network (VPN) is a network privacy and security tool that protects your personal data by routing traffic through a remote server.
When you connect to a VPN server, it replaces your IP address with the VPN server’s address, which helps keep your real location and identity private. A VPN service can also provide multiple other functions.
- Data encryption. A VPN creates an encrypted tunnel between your device and the VPN server, which helps protect your data in transit.
- Limiting ISP visibility. Your internet service provider (ISP) can see information about your connection, such as the websites you connect to. When you use a VPN, your ISP sees encrypted traffic instead of the contents of your browsing activity.
- Accessing intranets remotely. You can safely access your organization’s intranet from elsewhere with a remote access VPN.
- More secure connection on public networks. A VPN encrypts your traffic on public Wi-Fi, so others on the same network can't read it.
Many VPN users work remotely and use the VPN to create a secure, encrypted bridge so they can safely access company files from home without anyone spying on the data in transit.
Types of VPNs
VPNs come in different forms. Just like firewalls, they can be physical devices (hardware) or apps you install (software). As a VPN user, it helps to understand the four common types of VPN.
- Site-to-site VPN. Companies with multiple locations use this type of VPN to establish secure connections. Businesses also use site-to-site VPN to connect with a partner firm’s intranet.
- Remote access VPN. Employees use remote access VPNs to connect to the firm’s private network from home or elsewhere. Private users often use consumer VPN apps to protect their connection and improve privacy online.
- Mobile VPN. This VPN enables mobile users to access private networks on the go.
- Cloud VPN. This VPN connects users to cloud-based infrastructures.
You can also categorize VPNs based on the VPN protocol they use for encryption. For example, this would mean distinguishing between IKEv2 VPN and WireGuard VPN.
Firewall vs. VPN comparison
Firewalls and VPNs perform different, but complementary, network security functions.
A firewall sits at the edge of your network. It checks incoming and outgoing traffic against security rules and blocks connections that look suspicious or unauthorized.
A VPN protects your data as it travels across the internet. It encrypts your connection and routes traffic through a VPN server, which helps improve privacy on external networks.
| Feature | Firewall | VPN |
|---|---|---|
Main purpose | Protects your network and devices from outside threats. | Protects your internet traffic and privacy while data travels across the internet. |
How it works | Checks incoming and outgoing connection requests against predefined security rules and blocks anything unsafe or unauthorized. | Encrypts your internet traffic and sends it through a secure VPN connection. |
Protection | Helps detect and block malware and other threats that could damage devices or networks. | Protects the privacy of your online activities by encrypting your traffic. |
IP address | Doesn’t normally hide your IP address. | Replaces your IP address with the VPN server’s address. |
Where it protects you | Mainly protects the network and devices behind the firewall. | Protects your data while it travels between your device and the VPN server. |
Main benefit | Prevents unauthorized or dangerous traffic from entering or leaving your network. | Improves privacy and security when using the internet, especially on public or untrusted networks. |
In short, a firewall protects your network while a VPN protects the data leaving it.
What is a VPN firewall?
The term VPN firewall describes two different setups — two separate tools used together or one appliance that does both.
The first use of “VPN firewall” describes the practice of running a VPN alongside a firewall for stronger layered protection. This is standard practice for most organizations that take a layered security approach.
“VPN firewall” (or “firewall VPN”) can also mean a hardware appliance that combines a firewall with a built-in VPN capability, which has historically been used by small businesses and branch offices. The physical firewall VPN appliance is still used in on-premises networking, but is dated compared to today’s app-based consumer VPNs.
What are the main functions of VPN firewalls?
A VPN firewall combines two sets of functions — the firewall's and the VPN's.
- Filters network traffic. The firewall filters network traffic in a VPN connection, blocking suspicious or harmful data.
- Helps block malicious traffic. Firewalls can block suspicious or harmful connections before they reach your device.
- Reduced exposure to network threats. A firewall blocks many suspicious incoming connections before they reach your device.
- Protection from network-based attacks. A VPN replaces your IP address with the VPN server’s address, which makes it harder for websites and other online services to connect your activity to your real location. Because the firewall constantly filters network traffic, it provides better network-based attack prevention. An always-on firewall blocks most unsolicited inbound connections, making your network a harder target.
VPN firewall for home vs. a small business
Whether you need a VPN or firewall (or both) also depends on whether you’re looking for protection for your home or a business.
Home users generally have simpler needs than small businesses. If you're a home user, you probably need something that’s easy to set up, with straightforward security features and support for a small number of devices.
If you’re looking for a VPN firewall for a small business, you probably need a device that can handle more users and internet traffic. A small business firewall with VPN should also allow several people to connect at the same time, be easy to manage from one place, and allow remote users to securely connect.
VPNs and firewalls: Friends or foes?
A firewall vs. VPN comparison can make the tools seem like opposing options. In reality, firewalls filter traffic, while VPNs encrypt traffic. Firewalls restrict unwanted access, while VPNs protect data as it travels between your device and the VPN server.
However, the relationship between the two is symbiotic. As cybersecurity solutions, they complement each other and often come together in one device.
If you run an organization, using both firewall protection and a VPN is a good idea. A firewall protects the intranet from outside threats and helps ensure regulatory compliance. A well-configured firewall blocks unauthorized access attempts before they reach your network. Meanwhile, a VPN allows employees to work remotely with secure communication and access to all your company resources. Similarly, a VPN lets students access their university’s databases from home or elsewhere.
Organizations have good reasons to use VPNs and firewalls in combination. The two tools perform different functions that support cybersecurity and business continuity, and they can also be used together. The same logic applies to the VPN vs. traditional antivirus debate — a VPN secures your connection, an antivirus protects your device, and running both covers more ground than either alone.
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