Hello Nikos, > I have never tested the IPv6 support. The syntax at least should be: > ipv6-network = 2a01:x:y:z:: > ipv6-prefix = 64 I tried from Muscat, and my MTU was too small. I got the following error message: The MTU of the physical adapter is too small. An MTU of at least 1374 bytes is required for an IPv6 connection. Please contact your network administrator. Than I tried it from my lab in Germany and see the following packet in TCPDUMP: (infra) [~/work/ocserv] tcpdump -i vpns0 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on vpns0, link-type RAW (Raw IP), capture size 65535 bytes 15:22:50.642819 IP6 ::7539:eaff:a00:0 > fa-in-x93.1e100.net: ICMP6, echo request, seq 15, length 40 15:22:55.650385 IP6 ::7539:eaff:a00:0 > fa-in-x93.1e100.net: ICMP6, echo request, seq 16, length 40 The destination address is correct but the source address is broken. The screenshot supports that: https://thomas.glanzmann.de/tmp/ipv6.png My log shows: Jan 29 15:21:11 infra ocserv[17446]: 10.100.245.50:49224 assigned IPv6 to 'sithglan': [2a01:x:y:z::1%160212772]:2560 Jan 29 15:21:11 infra ocserv[17446]: 10.100.245.50:49224 assigning tun device vpns0 Jan 29 15:21:11 infra ocserv[17446]: [main] tun.c:90: vpns0: Error setting IPv6. Jan 29 15:21:11 infra ocserv[17446]: [main] tun.c:100: vpns0: Error setting DST IPv6. Jan 29 15:21:11 infra ocserv[17446]: 10.100.245.50:49224 user 'sithglan' of group 'sithglan' re-authenticated (using cookie) Jan 29 15:21:11 infra ocserv[17578]: 10.100.245.50:49224 TCP MSS is 1447 Jan 29 15:21:11 infra ocserv[17578]: 10.100.245.50:49224 DTLS ciphersuite: AES128-SHA Jan 29 15:21:11 infra ocserv[17578]: 10.100.245.50:49224 setting MTU to 1405 Jan 29 15:21:13 infra ocserv[17578]: 10.100.245.50:49224 setting up DTLS connection Jan 29 15:21:14 infra ocserv[17578]: 10.100.245.50:49224 setting MTU to 1339 Jan 29 15:21:14 infra ocserv[17578]: 10.100.245.50:49224 DTLS handshake completed (plaintext MTU: 1339) Okay there is something wrong in the code, I look if I'm able to hunt it down: ocserv[18438]: 10.100.245.50:49239 sending IPv4 10.12.12.189 ocserv[18438]: 10.100.245.50:49239 sending IPv6 ::a5cf:afff:a00:0 Full log: http://pbot.rmdir.de/LK9N2Qum3tIeDEP6_kZfIQ Cheers, Thomas
