Telfort's IPv6 is opt-in; you have to enable it in your Zyxel modem. This is how:
- Log in on your Zyxel modem at http://192.168.1.254/
- Go to Network Setting -> Broadband. At the top of that page, check which connection is used: VDSL or ADSL. Then find that entry in the table below, and click on the corresponding "Modify" icon on the far right
- In the windows that pops up, at "IPv6/IPv4 DualStack" click enable. More below, enable "6to4 Tunneling" and check "6RD Enable". Then click the Apply button
- Final check: the column IPv6 should now be on "enable" at your VDSL or ADSL line.
That's it. You should now have IPv6. Check via http://ip6.nl/ or http://test-ipv6.com/. If not, reboot your modem and computer once.
Technology used is 6RD. Address prefix is 2A00:CD8::/32
Telfort's mother company KPN yet has to introduce IPv6.