Is IPv6 supported?
Full IPv6 transport and payload support is available in OpenVPN 2.3.x.
The Windows TAP-driver included in OpenVPN 2.2-RC2 and later has support for IPv6 in TUN mode. In OpenVPN releases older than 2.2-RC2 there is limited support for IPv6. Point-to-point IPv6 tunnels are supported on OSes which have IPv6 TUN driver support (this includes Linux and the BSDs). IPv6 over TAP is always supported as is any other protocol which can run over Ethernet. When OpenVPN 2.0 is run in server mode, IPv6 is only supported in TAP mode, not TUN mode. The VPN carrier connection had to use IPv4 endpoints.