Imagine a company sending confidential data from its headquarters in New York to a research lab in Tokyo. That data needs to move quickly and securely, staying safe from anyone trying to intercept it. A site-to-site VPN makes that possible.
A site-to-site VPN links office locations together through an encrypted tunnel so they can work like one private system, even if they’re on the other side of the world. In this guide, we’ll cover what a site-to-site VPN is, how it works, and when to use one. We’ll also explore the pros and cons and how it compares to other types of VPNs.
What Is a Site-to-Site VPN?
Site-to-site VPNs create encrypted tunnels between multiple locations to send and receive data. The VPN tunnel is managed by gateways (usually routers or firewalls) at each location. These gateways sort all the traffic entering and leaving the network, blocking anything suspicious and filtering access to sites and apps.
Once the VPN is set up, everything works automatically in the background, so employees don’t need to log in or open an app to use it. Even though both networks are technically separate, a site-to-site VPN links them so they act like they’re part of the same system.
Businesses with multiple offices use site-to-site VPNs to privately share information between their locations. These VPNs let people access company files, apps, or tools in another office, even if it’s on the opposite side of the world. Information is shared securely, without anyone outside the network seeing it.
How Does a Site-to-Site VPN Work?
A site-to-site VPN needs five key components to keep multiple networks securely connected:
- VPN gateway: Each location has a VPN gateway that manages all incoming and outgoing network traffic.
- Authentication: The gateway at each location makes sure other gateways are trustworthy before any data is sent.
- Encrypted tunnel: An encrypted tunnel is created between both gateways to establish a secure communication pathway.
- Data encryption: Data is encrypted before it leaves either network. For example, if someone wants to send a budget spreadsheet, the information is encrypted before it leaves the first site. Even if someone successfully intercepts the data on its way to the other site, they won’t be able to read it.
- Data decryption: The gateways decrypt data as it arrives, so the person on the other network can read the file normally.
Most site-to-site VPNs use a protocol called IPsec to secure the tunnel. It encrypts the traffic, checks both networks are safe, and checks the integrity of the data as well. This makes sure data hasn’t been altered or tampered with as it moves between sites.
Types of Site-to-Site VPNs
Site-to-site VPNs fall into two main categories: intranet or extranet. The difference depends on who you’re connecting to.
Intranet-Based VPNs
Intranet-based VPNs connect different offices of the same company. They create a secure, shared private network for internal communication, so teams in different locations can work as if they’re on the same system. These VPNs are for internal use only, so no one outside of the workplace can connect to the network.
Extranet-Based VPNs
Extranet-based VPNs connect your network with trusted external parties, such as suppliers, clients, or contractors. They allow you to share access to certain files or systems while limiting others. This prevents third parties from reading internal resources you want to keep private.
Site-to-Site VPN vs Remote Access VPN
Site-to-site VPNs and remote access VPNs both secure traffic, but they work differently. A site-to-site VPN connects entire office networks. Once it’s set up, it runs in the background. You don’t need to install apps or log into a portal on every device, since everything connected to the network is covered automatically.
Site-to-site VPNs are also built for scale, so multiple devices in one office can access shared resources through a single connection to the VPN gateway. However, this only works when you’re physically on that network, so you’d need to be in the office or connected to the system. If you’re working from home, you can’t access the network through a site-to-site VPN.
A remote access VPN is for individuals. You download an app on your device to connect securely to your office network from anywhere. It’s ideal for remote workers who need access to company files and systems while they’re away from the office. Many companies use a combination of both types: site-to-site VPNs to link office locations and remote access VPNs to support remote working.
Site-to-Site VPN Benefits
Data Security
A site-to-site VPN encrypts all traffic between office locations, so even if someone intercepts it, they can’t read it. This helps protect sensitive files and emails from outside threats, which is especially important for companies sharing lots of sensitive data.
Simple Access Control
Once an office is connected to a site-to-site VPN, everyone on the network automatically has access to shared files from each office. This makes it easier to manage across offices because you don’t need to set up login rules and permissions for each location or person.
Seamless File Sharing
Site-to-site VPNs let teams work like they’re all in the same building, even if they’re thousands of miles apart. Employees can easily share files, access tools, and collaborate without worrying about safety or blocked connections. Because the networks are linked directly, you also don’t rely on third-party services to transfer data, which makes it more secure.
Flexible, Scalable Systems
If a company opens up a new office, it can be added to the VPN setup. Once the hardware is in place and the VPN tunnel is established, the new location becomes part of the existing network. Since there’s no need to build a separate system from scratch, site-to-site VPNs can be scaled for growing businesses.
No Apps Needed
Unlike remote access VPNs, people don’t need to install or manage VPN software on their devices. As long as they’re connected to the network, the VPN handles everything automatically, without you needing to log in or open an app.
Site-to-Site VPN Limitations
No Remote Support
Site-to-site VPNs only work if you’re connected to the network. That means you can’t open company files if you’re working remotely. This setup isn’t designed for remote access—it’s built for connecting fixed office locations.
More Sites, More Setup
Site-to-site VPNs can become more complicated to manage the more offices you have. For example, connecting 10 office locations might make things more complex than two or three. That’s because every office needs its own connection, which means managing multiple VPN tunnels. This setup is called a mesh network, and while it works well, it becomes harder to configure and maintain with higher numbers of offices.
Basic Security
The VPN keeps traffic secure between locations, but it doesn’t protect individual devices or data within the office. Once someone is on the network, they can move around freely and access anything they want. Site-to-site VPNs don’t include built-in threat detection or traffic filtering either. If someone in one office clicks on a malicious link, the VPN won’t block it. For more protection, you’ll need to combine the VPN with other cybersecurity tools like firewalls, antivirus software, and access permissions.
How to Create a Site-to-Site VPN
1. Choose a VPN Protocol and Check the Hardware
First, choose a VPN protocol to use. Most site-to-site VPNs use IPsec because it’s secure and supported by various types of networking equipment. So, even if one office uses Cisco equipment and another uses Fortinet, the VPN connection will still work smoothly. You’ll also need VPN-compatible hardware at each location to create the gateway—usually routers or firewalls that support site-to-site connections.
2. Configure the VPN Gateways
Each location needs its gateway set up with the right settings to recognize and trust other locations. This usually involves entering details like the other site’s network information and a shared password during authentication.
3. Set up Routing and Apply Security
Decide how data moves between locations (known as routing). Simple internet routing rules are fine for most setups, but you might want to use a more dynamic solution if you have a larger network. Dynamic routing works like a GPS for your data, automatically finding the best path and adjusting if something changes. This ensures traffic still reaches its destination without needing to update and change routes manually.
Once that’s done, set up any firewall rules or restrictions to control access between locations. You might allow access to some shared servers but not others, for instance.
4. Establish and Test the Connection
When everything is set up, you can establish the VPN tunnel between locations. Try accessing a shared file at another location to test the VPN. If you can open it, your tunnel is live and the VPN is running.
Is a Site-to-Site VPN Right for You?
A site-to-site VPN is a strong choice for companies that need to move data securely between multiple office locations. However, it’s not the right fit for everyone. If teams work from home or they’re often on the move, a remote access VPN is better suited.
Likewise, if you just want to keep your connection secure while working from home, running a small business, or traveling, CyberGhost VPN is a simpler and faster option. You can protect individual devices with our easy-to-use apps or set it up on your router to secure your whole network. Just download the app straight to your device to get strong encryption and secure your traffic wherever you go.
FAQ
A site-to-site VPN securely connects two or more office networks, so teams can share data over the internet without exposing anything to snoopers. It creates a private tunnel using encryption to keep internal communications safe.
Once it’s set up, you can test your VPN by trying to access a shared file or server from another connected location. If you can, the VPN is working.
Site-to-site VPNs use encryption to protect traffic between networks. Protocols like IPsec help keep data private, even if it travels across the public internet. However, site-to-site VPNs don’t protect individual devices inside the network, so you’ll need extra security tools like firewalls and antivirus software to keep them safe.
You’ll need VPN-compatible hardware, like firewalls or routers, that support VPN protocols. These act as your gateway at each site you want to connect. After setting up the gateways, you’ll need to configure routing rules, apply firewall settings, and test the connection. Read our step-by-step guide for more help.
Speed depends on your internet connection, hardware, and the amount of traffic between locations. Since everything runs through VPN gateways, your speeds can be hampered by outdated or overloaded equipment (for example, an old router). With a modern setup, you shouldn’t notice dips in speed.
Site-to-site VPNs make it easy to share files between locations, even if offices are on the other side of the world. They also encrypt data as it’s shared, which stops outsiders from snooping on company documents. You don’t need to install apps on every device either; every device connected to the network gets shared access automatically.
Yes. As long as both vendors support the same VPN protocol (usually IPsec), you can connect different hardware brands. For example, you can establish a VPN connection with a Cisco gateway in one office and a Fortinet device in another, as long as they both support the same protocol.
Yes. Dynamic routing is useful for larger setups, such as when connecting multiple offices in various locations. It helps your network automatically adjust if something changes, such as a lost connection. This ensures data can still be transferred easily without interruptions.
You can, but it requires careful setup. Each connection needs clear routing rules and access controls. Otherwise, traffic can be misrouted or exposed accidentally. You’ll also need to manage the flow of data between locations to avoid slow speeds or conflicts.
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