Frequently Asked Questions

If your IKEv2 VPN stopped working after updating to macOS 26 Tahoe and uses DES or 3DES encryption, the issue is due to a change in Apple’s VPN implementation. As part of broader security improvements, macOS 26 no longer supports outdated encryption algorithms like DES and 3DES for IKEv2 VPN connections. These algorithms are considered insecure by modern standards and have been removed from the built-in VPN client.

This change affects many older VPN setups—especially those used with legacy firewalls and routers—and leads to connection errors like “No acceptable proposal found” or “IKEv2 negotiation failed.”

VPN Tracker 365 continues to support DES, 3DES, and other legacy algorithms, allowing you to connect to your existing VPN without changing the gateway configuration. Learn more and get your VPN working again by following this step-by-step guide.