Not sure how to solve. But i got into this problem last week and working with AT&T and Connectech. The issue is similar to the one posted here. »U-Verse Static IP's: Not Working, Can't figure out problem
They dont seem to have any clue. For me it was working for the past 9 months suddenly stopped working. Also i can ping them internally and access inside the network or from my home. But if go outside and access these servers where my website is hosted i cannot access. Also the servers cannot access internet once i have the static ip assigned to the machines.
Please help me out.
Thanks in advance.