pretty sure the DNS is down.Tubehax DNS is now used to block auto-updates on Wii U, since Tubehax is now broken.
seriously? I stopped using Tubehax DNS cuz it stopped working a long time ago x.xIIRC some days ago this happened, i couldn't connet to internet for some short time. I think the DNS is just down and it will be usable in no time.
EDIT: It works now xD