Split Tunneling VPN Explained: How It Works and Why Use It

A split tunneling VPN allows you to choose which applications or data are protected by the VPN and which are not. It lets you selectively route only certain parts of your internet traffic through the encrypted VPN tunnel, while other traffic can access the internet directly without encryption.

Let's look at a real-world example. Imagine you're working remotely, and you need to access a secure customer database via the VPN. At the same time, you have a virtual team meeting on Zoom and your email client opens. 

With split tunneling, only your database access needs the VPN's protective shield while the Zoom call and email can go out directly through the internet. This way, you're not bogging down the VPN with non-essential traffic, meaning you get a smoother internet experience. 

However, it's important to manage split tunneling carefully. If not configured properly, sensitive data might inadvertently bypass the VPN, potentially exposing it to threats. You must strike the right balance between performance and security. 

This often involves setting strict policies or using specialized software that allows you to define which applications or services can go direct and which must go through the VPN.

How split tunneling enhances network efficiency

Split tunneling enhances network performance by selectively routing traffic. It allows your critical applications to benefit from the VPN’s security while offloading less important data traffic directly to the internet. This balance is essential for efficient and secure remote work.

Split tunneling is like opening a new lane on a congested highway exclusively for local traffic, allowing faster travel for non-essential vehicles while keeping the main lanes clear for critical traffic. 

The split tunneling feature does the same when you are on a company's VPN working from home. You can route your essential work applications through the VPN, ensuring they're secure. Meanwhile, your web browsing or streaming services can directly connect to the internet without using the VPN. This way, the network doesn't get bogged down with extra traffic.

For instance, say you need to access your internal CRM system to update client records. You would route this traffic through the VPN to keep it secure. At the same time, if you decide to play some background music on Spotify or quickly browse the news, that data doesn't need the VPN's security layer. It's non-essential traffic. So, it goes directly to the internet. 

The result? You get a faster browsing experience, and the company network remains largely unburdened.

Another example is when you are in a virtual team meeting on Microsoft Teams while running data analysis in the background. Your VPN primarily handles the data analysis task, safeguarding sensitive information. Meanwhile, the real-time audio and video of the meeting can bypass the VPN. This means less lag for the video call and a smoother discussion with your colleagues.

However, managing this balance is crucial. If split tunneling isn't configured properly, you might end up sending sensitive data outside the VPN inadvertently. That's risky because it could expose the data to potential threats. 

To avoid this, you can rely on strict policies or specialized software that lets you specify which applications must use the VPN. It's a way to ensure that even when aiming for efficiency, your security isn't compromised.

How split tunneling works

Split tunneling is a way to decide which of your internet activities must take the secure, albeit sometimes slower, route through the VPN, and which can take the "express lane" directly to the internet. 

Routing traffic through VPN vs. direct internet

When logged into your company's VPN from home, all of your online traffic doesn't have to go through the same tunnel. It's like having two roads: one robustly guarded, the other open for lighter, less sensitive travel. 

Say you are accessing a confidential document from your internal server. That traffic needs the VPN's protection. But if you are simply catching up on the latest cat videos on YouTube, that doesn't need to eat up the VPN's bandwidth. With split tunneling, you can do both without a hitch.

Here's a practical example: Consider your need to work on a secure financial report and, simultaneously, catch up on some news. The report requires the security blanket of the VPN, safeguarding sensitive company data. 

However, your quick news browsing can go straight to the web, freeing up resources and saving me from a potential slowdown. This way, you are not tying up the VPN with non-essential traffic.

Now, imagine you are on a Zoom call for a team meeting while having a file download in the background. The download is sensitive and thus, travels through the VPN. However, the Zoom call, which benefits from a faster connection, can go directly to the internet. This setup ensures you don’t miss a word during the meeting due to network lag.

The key is in the configuration. It's crucial to set up which data streams use the VPN and which don’t. If you accidentally send something secure outside the VPN, that's a danger zone. 

So, your IT team sets strict policies or uses software to ensure only specified apps use the VPN. This careful setup ensures you maintain seamless performance while keeping sensitive data safe and sound.

Types of split tunneling

Static split tunneling

This type is pretty straightforward. It's like setting a fixed route on a map. You decide upfront which applications or IP addresses will bypass the VPN and which will stay under its protective cover. 

For example, you might set it so that your email client always uses the VPN for security, but your social media browsing goes directly to the internet. Once these routes are set, they remain constant unless you tweak them manually. It's a solid way to ensure, say, your access to internal databases is always secured while your Spotify streaming doesn’t slow down the network.

Dynamic split tunneling

This type of split tunneling is a bit more flexible. Think of it as a smart GPS that changes the route based on traffic conditions. With dynamic split tunneling, the system can automatically decide, in real-time, the best path for the traffic. 

Let's say you start a secure web session with a client. The VPN dynamically routes this sensitive traffic through its tunnel. Meanwhile, if you decide to watch a quick YouTube tutorial on a new software tool, the system intelligently lets this traffic bypass the VPN, as it's not sensitive and requires a faster connection.

The real beauty of dynamic split tunneling is its adaptability. It responds to the current network environment and your activity. For instance, if you are connected to a public Wi-Fi hotspot at a café, the system might decide to route even more traffic through the VPN to heighten security, compared to when working from your secured home network. 

This adaptability means you get the best of both worlds—speed and security—without having to constantly adjust settings yourself.

So when should you use either type of VPN split tunneling?

In practice, these types offer different benefits. Static is great for consistent work environments where specific applications always need the same level of security. 

Dynamic is ideal for more variable conditions, where your internet use can change rapidly, requiring a more responsive approach to what goes through the VPN and what does not. Each has a role to play in keeping your network efficient while protecting the data that matters most.

Benefits of split tunneling for company networks

Improved bandwidth management

Picture your company's VPN as a busy highway. By routing only essential traffic through the VPN, you free up valuable bandwidth. This means your critical business applications run smoothly without the typical congestion that might occur when everyone is funneling all their traffic through the same channel.

Efficient use of network resources

Since non-essential traffic like casual web browsing or music streaming bypasses the VPN, these resources aren't bogged down. This strategic allocation ensures your sensitive applications get the priority they need. 

For example, when working on updating your internal CRM systems, you know the data is secured via the VPN. Meanwhile, if you need a quick break to listen to a podcast, it won't interfere with your network's performance. This setup means less strain on your infrastructure and more focus on what truly matters for business operations.

Enhanced performance

Reducing congestion on the VPN leads to enhanced performance, providing a seamless experience for everyone involved. Imagine having to join a virtual meeting from home. With split tunneling, your Microsoft Teams call is clearer and with less lag because it doesn't compete with other traffic.

Simultaneously, any ongoing data analysis tasks remain secure under the VPN's watchful eye. This separation ensures your meeting proceeds without a hitch and your colleagues also benefit from an optimized network experience.

Remote workers in particular appreciate the faster access to non-sensitive data. You can retrieve information that doesn't require VPN security quickly, improving your workflow efficiency. 

For instance, checking real-time market updates or accessing general industry news happens without the extra hurdle of VPN encryption, saving you time and reducing frustration. This speed enhances the overall user experience, making remote work not just feasible but enjoyable.

There’s also a financial upside:

Cost efficiency

By reducing the need for extensive bandwidth and lowering infrastructure costs, our company saves money. This is because you are not over-investing in bandwidth that supports all network traffic uniformly. 

Instead, you focus on what's critical. It allows you to allocate resources more effectively, potentially leading to investments in other areas of the business that could benefit from the freed-up budget.

In essence, split tunneling enables you to build a network environment that's both agile and secure. It addresses the needs of modern work practices by providing the flexibility to keep up with the dynamic nature of remote work, all while keeping an eye on performance and cost. It’s like having the best of both worlds—security where it’s needed most and efficiency where it’s most beneficial.

Security considerations for a split tunneling VPN

Potential risks

While a split tunneling VPN configuration definitely boosts efficiency, it can also open doors to potential risks. One of the biggest issues is exposure to unsecured websites. 

Imagine working from home and your browsing activity is split. While your access to company databases is securely tunneled through the VPN, your casual web browsing isn't. If you visit a malicious site, it could potentially compromise my device. Since that traffic doesn't have the VPN's protective layer, it's a bit like leaving the front door unlocked.

There's also the increased vulnerability to cyber threats. Without a doubt, split tunneling gives me the freedom to route certain traffic directly to the internet. But this freedom comes with a catch. 

If you are not careful, you might inadvertently allow sensitive information to slip through the cracks. With more traffic bypassing the VPN, there are more opportunities for hackers to intercept data. 

Even a simple thing like clicking on a phishing email can lead to trouble if those clicks aren't securely routed through the VPN. It's a delicate balance—getting the speed and accessibility you need while staying vigilant against potential threats.

Let's say you are on a public Wi-Fi network in a coffee shop. You are catching up on emails through the VPN while simultaneously streaming a video directly from the internet. That video stream isn't secure, and if the network is compromised, it could open up your device to further interference. It's crucial to be aware of your surroundings and ensure that sensitive tasks are always protected by the VPN.

Another thing to consider is the risk of data leakage. With split tunneling, there's always a chance that some data might unintentionally bypass the VPN. This happens when configurations aren't precise, or when new software doesn't adhere to the preset routing rules. 

For instance, if you install a new app that defaults to a direct internet connection rather than respecting the VPN settings, there's a risk that sensitive data could be exposed.

Mitigation strategies for security risks associated with split tunneling VPNs

Implementing strict access controls

Ensure that only authorized applications and IP addresses have the privilege to bypass the VPN. This essentially means creating a whitelist of approved services and websites that can use the direct internet path. 

For example, your Netflix binge-watching sessions won't ever sneak past these controls because they are properly set to prioritize work-related traffic. This ensures that only necessary and safe traffic is allowed to bypass the VPN, reducing the risk of data leaks.

Regularly updating security protocols

Keep all your applications and the VPN software up to date. Security updates often contain patches for vulnerabilities that could be exploited if left unattended. 

Your IT team must make it a practice to push these updates automatically. You must also ensure that firmware updates for routers and other network devices are completed without delay. It's like keeping the castle gates fortified to prevent any unwelcome guests.

Educating employees on safe internet practices

Even with the best technological safeguards in place, human error can be a weak point. Attend regular training sessions where you learn about identifying phishing attempts and understanding the implications of mixing personal and professional web activities. 

Being aware of the dangers of unsecured websites and how to spot them is part of your daily routine. For instance, make sure all my online shopping is done on secure, HTTPS websites, especially when not using the VPN's protective layer.

Use a password manager to generate and store strong, unique passwords

This minimizes the chances of unauthorized access to sensitive data. By reinforcing these practices across the company, you reduce the likelihood of accidental exposure to threats. It's about creating a culture of security consciousness that complements the technical measures already in place.

Combining these strategies helps maintain the balance between enjoying the benefits of split tunneling and keeping your network safe. Each step is a small part of a larger plan to ensure that while you embrace efficiency, you never let your guard down on security.

How to configure split tunneling in a VPN

Enabling split tunneling on a VPN involves adjusting the settings to ensure only specific traffic passes through the VPN, while other internet traffic flows directly to the internet. 

Windows OS

You start by modifying the VPN connection properties. Head to the Control Panel, navigate to Network and Sharing Center, and then move to Change Adapter Settings. Here, right-click on the VPN connection and select Properties. 

In the Networking tab, choose Internet Protocol Version 4 (TCP/IPv4) and click on Properties, followed by Advanced. There's a box labeled "Use default gateway on remote network" that I make sure is unchecked. This allows you to send non-essential traffic directly to the internet.

While connected to the VPN, you then add routes for the desired VPN subnets. Open a command prompt and type `ipconfig /all` to identify the VPN's interface name. With that information, use the `netsh interface ipv4 add route` command to specify which traffic should go through the VPN. 

For instance, if connecting to a secure internal server with a subnet of 192.168.1.0/24, you would route this traffic through the VPN by using the relevant command. If you want the route to persist even after a restart, you add `store=persistent` to the command. This ensures you don't have to reconfigure every time you reboot your computer.

MacOS

The process starts similarly. Go to the System Settings and open the VPN settings. There, in the Options section, uncheck "Send all traffic over VPN." This step is crucial in setting up split tunneling. 

For adding routes, fire up the Terminal. You must identify your Mac's network services by entering `sudo networksetup -listallnetworkservices`, which also requires my password. With that info, you enter a command setting additional routes for the VPN, like `sudo networksetup -setadditionalroutes "My-Meraki-Client-VPN" 192.168.2.0 255.255.255.0 ""`. This sends traffic to the desired subnet through the VPN interface.

It's essential to remember that you have to set up multiple routes at once if needed, as new routes overwrite the old ones on macOS. Verify the routes with `sudo networksetup -getadditionalroutes "My-Meraki-Client-VPN"`. 

While the routes in macOS are persistent, you might need to manually remove them when connecting to different networks to ensure your VPN traffic is sorted correctly. Keeping these routes updated ensures you maintain a balance between security for sensitive information and seamless access to non-critical data.

Best practices for a split tunneling VPN

Tailor split tunneling to company needs

It is essential to understand what kind of traffic your company handles. For instance, if you work in a company that regularly deals with sensitive client information, you will prioritize securing that data through the VPN. 

On the other hand, for less critical tasks, like accessing public databases or streaming industry webinars, you would route that traffic directly to the internet. This prioritization ensures that the VPN isn't overloaded with data that doesn't require encryption.

Monitor the network

Regular audits help you spot any unusual traffic patterns that could indicate a misconfiguration or a potential threat. For example, if you notice an influx of direct internet traffic during peak hours, it might prompt you to review your split tunneling rules. 

Perhaps an application that should be secured by the VPN is bypassing it, or maybe a non-essential app is eating up too much bandwidth. By maintaining a vigilant eye on the network traffic, you can make informed decisions and tweak settings as necessary.

Using robust monitoring tools helps a lot in this endeavor. You can rely on network monitoring software that provides real-time analytics. These tools alert you if there's a sudden change in traffic patterns, allowing you to address issues swiftly. 

For instance, if your monitoring software indicates a spike in data being sent directly to the internet, you can quickly investigate and adjust the split tunneling configurations or even temporarily disable the feature for specific applications until you figure out the cause.

Regularly review and update your security policies

As your company’s needs evolve, so should the split tunneling configurations. If we adopt a new cloud service, integrating it into the VPN policies ensures that sensitive data transferred through this service receives adequate protection. 

Conversely, if you start using a high-bandwidth application that doesn't handle sensitive information, configuring it to bypass the VPN can help maintain overall network performance without compromising security.

Train your staff on split tunneling

Training sessions help keep everyone on the same page. By educating colleagues about how split tunneling works and why specific configurations are set, you foster a culture of security awareness. 

For instance, explaining to them why their streaming service bypasses the VPN while email does not, helps everyone understand the rationale behind our network setup. It also encourages them to report issues if they notice something off in their internet performance.

Tailoring split tunneling effectively means aligning it with the company's unique operational needs while keeping a strong focus on network health. It's about being proactive, informed, and adaptable to changes. By applying these best practices, you ensure that split tunneling enhances your network's efficiency without compromising the security that’s vital to your business operations.

How Netmaker Enhances Network Efficiency & Security

Netmaker offers a robust solution for managing split tunneling VPNs by providing features such as Egress and Internet Gateways. These allow specific traffic to bypass the VPN while ensuring sensitive data remains secure. 

With Netmaker's Egress Gateway, you can direct non-essential traffic, like streaming services or web browsing, to the internet while keeping critical applications secured through the VPN. This selective routing optimizes bandwidth management and reduces congestion on the VPN, enhancing network performance and user experience for remote workers.

Additionally, Netmaker's Remote Access Client (RAC) and Access Control Lists (ACLs) provide granular control over network access, ensuring that only authorized applications and data streams utilize the VPN. This minimizes risks associated with split tunneling by preventing unauthorized traffic from bypassing security measures. 

By using Netmaker, companies can effectively balance the need for speed and efficiency with robust security protocols. Sign up with Netmaker to start leveraging these capabilities in your company network.