From another thread:
If you are a Comcast customer, their XFi Advanced Security features block the requests from coming into the Xbox for the official server. You need to allow these requests or disable the feature.
From another thread:
If you are a Comcast customer, their XFi Advanced Security features block the requests from coming into the Xbox for the official server. You need to allow these requests or disable the feature.
Interesting, thanks for the heads up. I'll pass this along to our host too. Would be great to know if you have further instructions on how that setting could be changed.
I've followed up with our hosts for some additional information to help us run tests to identify what's precisely happening here, hopefully we can get to the bottom of this as soon as possible.
Thank you for all the info guys!
We'll have it fixed in an upcoming patch