Openvpn leaking IPV6

[ankhazam]

Hi,
I have a issue with my AX88U. I set up the Openvpn server to:

• use VPN to access both LAN and WAN
• advertise DNS to clients
• no extra custom config.

The case is when I connect to the router from a client that has both IPV4 and IPV6... only the IPV4 traffic is routed through the tunnel whereas IPV6 is ignored and leaks using my client local connection...

Is it possible to harden the tunnel so that:
1) both IPV4 and IPV6 go through the tunnel (my AX88U ISP supports IPV6) or
2) force the client (W10, Android) to use the IPV4 tunnel and disable IPV6 upon connecting to the server...

Having to manually disable IPv6 stack on W10 is a tedious solution and on Android it is even impossible.

Thanks,
Ank

 

[drabisan]

I don't have ipv6 on my Asus but I do understand your problem.
If you don't/can't tunnel both ipv4 and ipv6, a client that has ipv6 will use that stack and traffic will user local network rather that going via openvpn tunnel.
Asus' openvpn server is 2.4something and ipv6 support in openvpn is since 2.3.
So, in theory, interface should allow you to configure tunnel for both ipv4 and ipv6. (again, I can check that, I don't have ipv6 on Asus so I don't know if the interface gets "smarter" when it knows you gave ipv6).

If the Asus interface doesn't allow that...I don't know/think editing /tmp/etc/openvpn/server1/config.ovpn will persist.
And also manually editing client.ovpn on your laptop.

 

[ankhazam]

Exactly.. hence I would see solutions:
1) try to configure the Openvpn on router so that in TUN mode it serves both IPV4 and IPV6...
@RMerlin, would that be possible? I managed to make it work in TAP mode... but Android does support that

2) create a client config file and/or configure the server so that it forces both ipv4 and ipv6 traffic through the TAP adapter or any other way that would successfully disable/debilitate/disarm/locally loopback? the client's native IPV6 stack so that it only support the IPV4 traffic over the tunnel whilst connected.