[ipv6-wg] IPv6 Only Network at RIPE 67

* Gert Doering

> *wake up*.  OpenVPN IPv6 development team here :-) - what's breaking
> for you?

I'm successfully using OpenVPN on the IPv6-only LAN. However there are a
few caveats:

1) I need move /usr/sbin/openvpn aside and replace it with a wrapper
script that substitutes "udp" and "tcp-client" with "udp6" and
"tcp6-server" in the arguments list before exec-ing the real binary.
This is because NetworkManager doesn't support the explicit IPv6
protocol definitions, and likely never will either as they are likely
going away in the future.

2) I need to use TCP, because the server at work does not support
UDP/IPv6 because enabling that in turn breaks --multihome for IPv4
clients: https://community.openvpn.net/openvpn/ticket/306

3) The OpenVPN server pushes a DNS server which gets higher priority
than the DNS64 one here, which in turn breaks NAT64 and access to
IPv4-only content. I found no way to override this in NM-OpenVPN,
although I suppose I could do chattr +i /etc/resolv.conf instead... (not
saying this is a bug in OpenVPN, more a general caveat when doing VPN
from NAT64/DNS64 networks).

Tore