My ISP is Unitymedia NRW, Germany. It it a cable (like TV) ISP which has given me a Technicolor TC7200 modem/router. The ISP uses DS-Lite, so I only have a public IPv6 address, and no IPv4 address. This works, except that the modem/router has such limited options and can be managed remotely, that I would like to have my own router between the ISP and my home network.
When I just have the TC7200, my computer has the following global IPv6 addresses:
When I access pages like
facebook.com the Firefox plugin “IPvFox” shows me that they indeed load over IPv6.
Now I bought a TP-Link WDR3600 router and set it between my computer and the modem, like route B here:
I set the WAN of the WDR3600 to obtain an IPv6 address via DHCPv6. That works, it gets an IP address. Then, it uses DHCPv6 to assign IPv6 addresses to the connected devices. That works as well, I get an IPv6 address on my computer. From inside out, those are the IPv6 addresses of the whole thing:
2a02:908:f421:7600:f2de:f1ff:fede:a290/128 Computer LAN 2a02:908:f421:7600:ea94:f6ff:fed4:2624/64 WDR3600 LAN 2a02:908:f421:7600::e/64 WDR3600 WAN 2a02:908:f421:7600:ce35:40ff:fee0:9498/64 TC7200 LAN 2a02:908:f400:2:31c9:7cf5:eb4:75e2/128 TC7200 WAN
When I open
google.com, it takes a very long time, then it loads the content quickly over IPv4. I assume that it tries via IPv6 but fails after a timeout.
facebook.com is quickly loaded, but also over IPv4.
So I managed to break IPv6 connectivity. I really would like to have a router under my control between the ISP and my home network, but having no IPv6 connectivity seems like a bad idea.
In another forum (German), somebody mentioned that this behavior is expected from most routers. Except for routers running OpenWrt with the latest version, Barrier Breaker. Is there some way I can with the original firmware? They have a simulator online. You can go into the “IPv6 Support” and look at all the options that it has.