Frequently Asked Questions
Why may an IKEv2 VPN connection suddenly fail to connect?
Symptoms:
The VPN connection setup fails or gets stuck during startup. The server is reachable, but the tunnel is not established.
Cause:
Jumbo frames may be enabled on the client's network. The resulting increased MTU was not fully supported across the network path, causing VPN packets to be lost.
Solution:
Disable jumbo frames on the client's network or configure a standard MTU. After disabling jumbo frames, processes that determine and apply the correct path MTU can work properly, allowing the tunnel to be established.