For the past month I’ve been beta testing the DNS services of playmo.tv to access my Netflix account while outside the US. It’s very simple, sign up, and change the DNS settings on your compatible devices. In the network settings of the Apple TV I switched the LAN configuration from DHCP to manual, kept the IP and subnet but updated the DNS address (originally pointing to the router which was downstream from my ISP DNS) with the DNS servers provided with my playmo account. After rebooting the AppleTV I was surprised to find I had no internet service at all. Clicking on the network configuration again should that it was manual IP, Subnet, and router, but now the DNS was changed not to the one I specified but to the IPv6 DNS of the router.
I repeated this 2 more times hoping it was some kind of error but the results were the same. DNS I entered was gone, replaced by the automatically completed IPv6 DNS address. My family was starting to get bothered (since they only complain when things break) and as a quick fix I disabled the IPv6 DHCP service on the router. Rebooting the Apple TV one more time got me connected to the iTunes Store and now Netflix.
So in summary if you want to use the Apple TV with a DNS forwarding service like playmo you’ll need to disable IPv6 services on your router. For the moment it isn’t a big problem but I’d like for Apple to fix this bug in their network stack.