IPv4 vs IPv6 for VPN and Proxy Connections

Understand how IPv4 and IPv6 can affect access, DNS, TUN and connection failures.

Why it matters

Some networks, endpoints or local configurations handle IPv6 differently, so an IPv6 result can fail even when IPv4 works.

How to diagnose

Test IPv4 and IPv6 separately, inspect DNS answers and review TUN routing and client IPv6 settings.

Do not disable IPv6 by default

Disabling IPv6 changes system behavior. Diagnose the actual problem first.

Keep it reproducible

Change one network setting at a time and test after each change.