If you have AT&T U-Verse, from time to time you may have issues with Facebook or Google sites like Youtube not working, while the rest of the Internet works fine.
The solution is simple but non-obvious: Disable IPv6.
IPv6 is a 21st-century network technology that Google and Facebook implemented because they know they’re going to need it and they don’t like to wait until the last minute, and AT&T’s implementation isn’t quite up to par. Dig deep enough into AT&T’s support forums, and their recommendation if you’re having IPv6 issues is just to disable it.
On my 3801HGV gateway, you navigate to Settings, LAN, IPv6 and there’s a checkmark to enable IPv6. Uncheck that box, then click Save.
I hate to disable IPv6 because there will come a time when we will need it for almost everything, but until AT&T gets its act together, this workaround will get the sites your kids want to use working. The problems tend to be intermittent–AT&T has had IPv6 enabled for two or three years and I haven’t had issues until recently–but eventually they’ll figure it out, and hopefully it will be before the majority of the sites we use start requiring IPv6 for everything.