Summary  
This chapter covers split tunneling: defining routing rules that send specific traffic through an encrypted VPN tunnel while letting other traffic bypass it to balance security and performance.

General domain of usage  
VPN configuration

**Video: Split Tunneling in VPNs — Security and Performance Impact**

This video provides a clear explanation of what split tunneling is, how it works in VPN environments, and explores both the security implications and the performance benefits of using split tunneling. You'll see visualizations of network traffic flows with and without split tunneling, and learn when it's appropriate to enable this feature.

Split tunneling is a VPN feature that allows you to select which network traffic is routed through the VPN tunnel and which traffic uses your regular internet connection. With split tunneling enabled, only specific applications, IP addresses, or types of traffic are sent securely through the VPN, while the rest bypasses the VPN and accesses the internet directly. This selective routing can be configured based on security requirements or performance needs.

While **split tunneling** can improve speed and reduce bandwidth usage by allowing non-sensitive traffic to bypass the VPN, it also introduces security risks. If some traffic leaves your device outside the VPN tunnel, it is not protected by **encryption** or the VPN's privacy features. This can lead to **data leakage**, making your device or network more vulnerable to attacks. Use split tunneling only when necessary, such as to access local network resources or improve performance for trusted activities, and avoid it when handling sensitive information or in high-risk environments.

```
# Example OpenVPN client configuration for split tunneling

# Prevents OpenVPN from automatically routing all traffic through the VPN
route-nopull

# Only routes traffic destined for the 10.0.0.0/24 network through the VPN
route 10.0.0.0 255.255.255.0
```

In this OpenVPN configuration, the `route-nopull` directive stops the VPN from redirecting all your internet traffic through the tunnel. The `route 10.0.0.0 255.255.255.0` line then specifies that only traffic destined for the `10.0.0.0/24` subnet will use the VPN. All other traffic will take the default route outside the VPN, effectively implementing **split tunneling** for that specific network segment.

What is a potential risk of split tunneling?

A comprehensive theoretical course on VPN technologies, focusing on the internal workings of VPNs, tunneling protocols, encryption, authentication, secure communication, architectures, and security considerations. Designed for networking and cybersecurity professionals seeking a deep understanding of VPNs with practical configuration examples and real-world scenarios.

This section introduces the foundational concepts of VPNs, their purposes, and the basic principles behind secure tunneling and remote connectivity.

This section delves into the technical mechanisms behind VPNs, focusing on tunneling protocols, encryption methods, and authentication techniques.

This section covers the design of VPN deployments, common architectures, and the security risks and best practices associated with VPNs.

Split Tunneling and Traffic Management