Unable to use AirVPN from my desktop when my server acts as DNS/DHCP

[zoidberg2]

I'm using Ubuntu 14.04 on my Desktop & server. I am unable to use Airvpn to connect to sites blocked by my ISP when I use my Ubuntu Server as my DNS & DHCP server.


When I power the server down & use my ISP router as the DNS & DHCP server I'm able to use Airvpn no problem but when I try doing with my server up running DNS & DHCP I'm getting messages that sites are blocked despite the fact Airvpn says it is now connected to their server.



When I google what is my public IP I'm getting an IP address similar to this 2a02:c7d:4e26:with 5 more octets, I'm assuming it is an IPV6 address) instead of my public IPV4 class that I get when I try searching for my public IP when the router is set up as the DHCP/DNS server. I'm getting this long IP address both when I'm connected & disconnected from Airvpn.





A few things I tried to resolve the issue was,
I had set the computer as a static IP address, using it's MAC address I now have the DHCP server assigning it an IP address.

Deleted my history & cache in the browser.

Cleared my DNS cache
Restarted the DHCP & Bind services on the server
Changed my DNS forwarder IP to another DNS server


Any help would be greatly appreciated.


***Disable IPv6 fixes this issue

To disable ipv6, you have to open /etc/sysctl.conf using any text editor and insert the following lines at the end:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

If ipv6 is still not disabled, then the problem is that sysctl.conf is still not activated.

To solve this, open a terminal(Ctrl+Alt+T) and type the command,

sudo sysctl -p

You will see this in the terminal:

net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

After that, if you run:

$ cat /proc/sys/net/ipv6/conf/all/disable_ipv6

It will report:

1


If you see 1, ipv6 has been successfully disabled.