You can't change their DHCP'ed DNS but if you run an internal wireless network set your own internal DNS to Google, 8.8.8.8/8.8.4.4 and not only will DNS be an order of magnitude faster it will never fail. Ive done this since the last major ATT DNS outage in 2011 and have never looked back. YMMV.
Thanks for the info. I think I'm going to give it a go with google's dns and see how it compares to the opendns .. I figure either one is going to be better than the u-verse one.
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