Hello Nikos, I just wanted to let you know that AnyConnect now works with IPv6 like a charm. Thank you for the fix. I'm currently using it. Jan 30 10:13:16 infra ocserv[10334]: 85.154.119.84:50691 assigned IPv4 to 'sithglan': 10.12.12.155 Jan 30 10:13:16 infra ocserv[10334]: 85.154.119.84:50691 assigned IPv6 to 'sithglan': 2a01:4f8:bb:5fd:0:a:c0c:9a01 The problem with the MTU was really that I had set my mtu a long time ago on Windows to 1400 and never changed it back. The reason for that was that a customer side had MTU Discovery problems and I needed circumvent the bug. I ran the following command to correct the MTU: Start => cmd => Right click execute as administrator netsh interface ipv4 set subinterface "Local Area Connection" mtu=1500 store=persistent Thanks a lot for fixing this as well. I tested the following version: 7129b7b316e8ef8388e03c49e6c521d71d813705 Cheers, Thomas