IPv6 Connectivity

[Thomas Glanzmann]

Hello Nikos,

> Indeed. I realized that in Linux there is black magic involved to set
> an IPv6 address to a device. The same ioctl is used (SIOCSIFADDR) but
> a different structure is passed (in6_ifreq) which isn't typically
> defined. Moreover SIOCGIFADDR isn't able to read the IPv6 address.

probably you or I should have a look at the OpenVPN code. Many years ago I
added a few lines to OpenVPN to support IPv6 for FreeBSD, OpenBSD and NetBSD.
:-)

http://swupdate.openvpn.org/community/releases/openvpn-2.3.2.tar.gz

> I think also that my assumption that a tun device allows for both an
> IPv4 and IPv6 address isn't true. So indeed IPv6 support is broken and
> requires quite some changes.

You can set an IPv4 and IPv6 address to a device in Linux, I dod that on
regular basis. I have multiple OpenVPN tun devices with the same:


(infra) [~] ip a s dev r28
14: r28: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1400 qdisc pfifo_fast state UNKNOWN qlen 100
    link/none
    inet 10.255.254.1 peer 10.253.232.1/32 scope global r28
       valid_lft forever preferred_lft forever
    inet6 fe80::1/64 scope link
       valid_lft forever preferred_lft forever

For example this one.

Cheers,
        Thomas