VPN Split Tunneling - Benefits and Security Trade-offs

About 2 min read

VPN split tunneling is a configuration in which, rather than routing all traffic through the VPN when connected, only specific traffic is sent through the VPN tunnel while the rest connects directly to the internet. With the spread of remote work, many companies have adopted it to optimize bandwidth and improve the user experience. As of 2025, with the spread of SASE (Secure Access Service Edge), new architectures that integrate split tunneling with cloud security are becoming mainstream.

Real-World Use Case

"After migrating to remote work, the VPN server's bandwidth became congested and the quality of video meetings dropped significantly. When we moved Microsoft 365 and Zoom traffic outside the VPN using split tunneling, VPN bandwidth utilization dropped by 60% and work efficiency improved dramatically."

Split Tunneling Conceptual Diagram

Comparison with Full Tunneling

Full tunneling (routing all traffic through the VPN) offers high security because all traffic can be inspected by the company's security appliances, but the load concentrates on the VPN server, which can degrade the quality of video meetings such as Zoom and Teams. With split tunneling, only access to internal systems goes through the VPN while SaaS and general internet browsing connect directly, so in some cases bandwidth can be reduced by 50 to 70%.VPN design primers (Amazon) offer a systematic way to learn.

Security Risks and Countermeasures

The biggest risk of split tunneling is that traffic not routed through the VPN falls outside the company's security monitoring. A device infected with malware could communicate with a C2 server via a path outside the VPN. Effective countermeasures include strengthening endpoint security, protecting DNS queries with DNS over HTTPS, and gaining visibility into SaaS usage with a CASB (Cloud Access Security Broker). Protect your VPN connection account with a strong, random password and secure the remote work environment.network security books (Amazon) are also a helpful reference.