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Trying to learn how IPv6 works with OpenVPN, so I wanted to setup following scheme.

I have a VPS server (Ubuntu), which have been allocated a /48 subnet.

ISP ipv6 gateway is XXXX:XXXX:XXXX::1
Server ipv6 address is XXXX:XXXX:XXXX:39::1

The idea is that any clients connecting to server gets an ip address on the XXXX:XXXX:XXXX:39:2::/64 subnet.

Server configuration file is based on the sample configuration from OpenVPN with the following additions:

dev tun
server-ipv6 XXXX:XXXX:XXXX:39:2::/64
push "route-ipv6 XXXX:XXXX:XXXX:39::/48"

Restarting OpenVPN server gave no problems.

Server is assigned following ip addresses:

eth0: XXXX:XXXX:XXXX:39::1/48
tun0: XXXX:XXXX:XXXX:39::2/64

Client is assigned:

OpenVPN tap: XXXX:XXXX:XXXX:39:2:0:1:0, and I can ping XXXX:XXXX:XXXX:39::1 just fine. However pinging ISP gateway from client makes connection time out.

I can ping ISP ipv6 gateway from server.

I have allowed traffic from XXXX:XXXX:XXXX:39:2::/64 in Ubuntu Firewall.

What am I missing?

I should mention server is running OpenVPN version 2.2.1 - is that the reason for the complaining?

share|improve this question
is the subnet from your VPS provider on-link or routed? if it isn't routed, you will need to proxy NDP for your ISP's side. – Olipro Jun 2 '13 at 16:56
Noooo. Different interfaces belong in different subnets! Fix that first. – Michael Hampton Jun 2 '13 at 17:50
Yes I was suspecting different subnet was needed for tun0 interface. Ideal situation would be VPN connected clients is sitting behind the equivalent of NAT for ipv6, but is there an equivalent of 10.x.x.x/8, 172.16.0.x/16 and 192.168.x.x/32 for ipv6? – Lasse Michael Mølgaard Jun 3 '13 at 22:24

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