Understanding What is Virtual Private Network (VPN) Passthrough

Welcome to my article on VPN passthrough, where we will explore its definition, functionality, benefits, and more. If you’ve ever wondered what VPN passthrough is and how it works, you’ve come to the right place. Let’s dive in!

Key Takeaways:

• VPN passthrough allows outbound VPN connections to pass through a router’s firewall.
• It enables the movement of VPN traffic without being slowed or blocked.
• VPN passthrough is not the same as a VPN router, as it doesn’t encrypt traffic.
• Understanding how VPN passthrough works requires knowledge of Network Address Translation (NAT).
• Enabling VPN passthrough can be beneficial for organizations that use legacy VPN protocols.

How Does VPN Passthrough Work?

To understand how VPN passthrough works, it is important to first understand the functionality of Network Address Translation (NAT). NAT is a tool used by routers to filter and protect network traffic. However, it can sometimes interfere with VPN connections due to the encryption used by VPN protocols.

VPN passthrough solves this issue by allowing VPN traffic to pass through the router without being blocked. It achieves this by modifying the headers of VPN packets to provide the necessary information for NAT to function properly.

Unlike a VPN router, which encrypts all network traffic, VPN passthrough only allows VPN traffic to pass through without encryption. This means that devices connected to the network are not protected by the VPN’s encryption. However, VPN passthrough can be useful for organizations that still rely on older VPN protocols, such as IPsec or PPTP, which may not be compatible with NAT.

What is IPsec Passthrough?

The IPsec Passthrough is a feature that allows IPsec tunnels to pass through a router’s firewall without being blocked. It enables the establishment of secure connections using the IPsec protocol. It is important to note that IPsec Passthrough should not be confused with VPN Passthrough, as the former is specific to the IPsec protocol, while the latter refers to the general functionality of allowing VPN traffic to pass through a router.

To understand the functionality of IPsec Passthrough, it is essential to consider the interaction between the IPsec protocol and Network Address Translation (NAT). NAT is a tool commonly used in routers to filter and protect network traffic. However, NAT can interfere with VPN connections due to the encryption used by VPN protocols. IPsec Passthrough addresses this issue by modifying the headers of IPsec packets, providing the necessary information for NAT to function properly and allowing the packets to pass through the router’s firewall.

In comparison, VPN Passthrough refers to the general capability of a router to allow outbound VPN connections to pass through without being slowed or blocked. It encompasses various VPN protocols, while IPsec Passthrough is specifically tailored to the IPsec protocol. By enabling IPsec Passthrough, organizations can ensure the smooth flow of IPsec traffic while maintaining the security benefits provided by NAT.

Advantages of VPN Passthrough

Enabling VPN passthrough on your router can provide several benefits, particularly if you need to use older VPN protocols that are not compatible with Network Address Translation (NAT). Here are some advantages of VPN passthrough:

• Compatibility with older VPN protocols: VPN passthrough allows you to use legacy VPN protocols such as IPsec and PPTP. While newer protocols like OpenVPN and WireGuard are recommended for their enhanced security, some organizations may still rely on older protocols. Enabling VPN passthrough ensures that these protocols can function properly.
• Ease of setup: VPN passthrough is typically enabled by default on most routers. This means that you may not need to manually configure any settings if you want to use older VPN protocols. It streamlines the setup process and saves you time.
• Flexibility: By enabling VPN passthrough, you have the flexibility to choose between different VPN protocols based on your specific requirements. This can be useful if you need to connect to networks that use different protocols or if you encounter compatibility issues with newer protocols.

Overall, VPN passthrough provides a convenient solution for those who require the use of older VPN protocols. It allows you to maintain connectivity and secure your network without the need for a dedicated VPN router or complex configuration processes.

VPN Passthrough Benefits

Table: Comparison of VPN Passthrough Benefits

Disadvantages of VPN Passthrough

While VPN passthrough can be a useful feature for allowing outbound VPN connections to pass through a router’s firewall, it does have its disadvantages and limitations. Understanding these drawbacks can help users make informed decisions when it comes to enabling VPN passthrough.

NAT Compatibility

One significant limitation of VPN passthrough is its compatibility with Network Address Translation (NAT). VPN protocols that use encryption can sometimes be hindered by NAT, as it modifies the headers of network packets. While VPN passthrough attempts to overcome this issue by modifying VPN packet headers, it may not always be successful or reliable. This can result in connectivity issues and unreliable VPN connections when using older VPN protocols that rely on VPN passthrough.

Security Vulnerabilities

Another disadvantage of VPN passthrough is the inherent vulnerabilities of older VPN protocols. While newer protocols like OpenVPN and WireGuard offer stronger encryption and security features, older protocols like IPsec and PPTP are considered less secure. Enabling VPN passthrough for these older protocols can expose network traffic to potential security risks and compromises. It is essential to weigh the security implications before opting for VPN passthrough.

Router Performance

Enabling VPN passthrough on a router can also impact its performance, specifically the router’s CPU. The process of modifying VPN packet headers and handling VPN traffic can put a load on the router’s CPU, leading to slower computational times and potentially affecting other network operations. This can be particularly noticeable when multiple VPN connections are active simultaneously, further impacting the router’s performance and stability.

It is crucial to consider these disadvantages and limitations before enabling VPN passthrough. While it may be necessary for organizations or users relying on older VPN protocols, it is recommended to evaluate the security risks and explore alternatives like modern and more secure VPN protocols that do not rely on VPN passthrough.

How to Enable VPN Passthrough

In order to enable VPN passthrough on your router, you will need to access the router’s settings. The exact method for enabling VPN passthrough may vary depending on the model and brand of your router, but the general steps are as follows:

1. Open a web browser on a device connected to the network.
2. Enter the IP address of your router into the browser’s address bar. This IP address is typically printed on a sticker on the router itself or can be found in the router’s manual.
3. Enter your router’s username and password when prompted. If you haven’t changed these credentials, they are often set to the default values listed in the router’s manual.
4. Once logged in, navigate to the settings page for your router. Look for a tab or section labeled “Enable VPN Passthrough” or “Virtual Server.”
5. Toggle the VPN passthrough option to enable it. Some routers may have individual options for different VPN protocols such as IPsec or PPTP.
6. Save the changes and exit the router’s settings. The VPN passthrough feature should now be enabled, allowing outbound VPN connections to pass through the router’s firewall.

It’s worth noting that many routers have VPN passthrough enabled by default, so manual configuration may not be necessary if you are using a modern VPN protocol like OpenVPN or WireGuard. However, if you encounter any issues with older VPN protocols, enabling VPN passthrough can help ensure smooth and uninterrupted VPN connectivity.

Remember, the process for enabling VPN passthrough may vary depending on your specific router model, so it’s always a good idea to consult the router’s manual or contact the manufacturer’s support for detailed instructions.

Do You Need VPN Passthrough?

In most cases, VPN passthrough is not necessary unless you specifically need to use older VPN protocols that are not compatible with NAT. Modern VPN protocols like OpenVPN and WireGuard can bypass NAT on their own, making VPN passthrough unnecessary. It is recommended to use up-to-date protocols for better speeds and stronger security.

There are, however, certain use cases where VPN passthrough may still be beneficial. For example, if you are part of an organization that relies on legacy VPN protocols such as IPsec or PPTP, enabling VPN passthrough can allow you to continue using these protocols without any issues. It can be especially useful if your organization has not yet transitioned to newer and more secure VPN protocols.

Additionally, there may be instances where you encounter compatibility issues with modern VPN protocols and certain network configurations. In such cases, enabling VPN passthrough can be a temporary workaround to ensure smooth VPN connections. However, it is important to note that this should only be done after careful consideration of the security implications and limitations of older VPN protocols.

Table: Use Cases for VPN Passthrough

Overall, the necessity of VPN passthrough will depend on your specific requirements and circumstances. It is important to evaluate the security, performance, and compatibility aspects before deciding whether to enable VPN passthrough on your router.

Conclusion

In conclusion, understanding and enabling VPN passthrough on your router can be beneficial in certain scenarios. VPN passthrough allows outbound VPN connections to pass through the router’s firewall, making it useful for older VPN protocols that are not compatible with NAT. However, it’s important to note that VPN passthrough may not be necessary for modern VPN protocols that can bypass NAT on their own.

When deciding whether to enable VPN passthrough, it’s essential to consider the advantages and disadvantages. While VPN passthrough allows the use of legacy VPN protocols, which may still be required by some organizations, it’s important to weigh the security and performance limitations of these older protocols. For better speeds and stronger security, modern VPN protocols like OpenVPN and WireGuard are recommended.

Ultimately, the decision to enable VPN passthrough should be based on your specific needs and requirements. It’s recommended to evaluate the VPN protocols you intend to use and determine if VPN passthrough is necessary. By understanding the functionality, benefits, and limitations of VPN passthrough, you can make an informed decision that aligns with your security and performance goals.

Matt Böhmichen

Matt is doing business in information technology since 1992. After discovering Linux he soon fell in live with Windows Operating System.