Why can't I access google.com when tethering? I am paying my wireless carrier (MetroPCS) for the "hotspot" feature, which is required in order for me to tether. However, strange things are a happening....

I can't access google.com, although I can access it via IP address - 208.54.90.53. Which leads me to believe it has something to do with DNS resolution.

HOWEVER

I can access android.stackexchange.com directly.

BUT

I can't access facebook.com either directly or via IP.

... I've tested this on multiple laptops, and the issue is the same. What in the world is going on?
Once I disconnected my other LAN and Wifi connection that were connected but had no internet, it worked. Before I had no FB or Google as you say. Must have been a conflict