I keep getting this message whenever I attempt to log on. It goes to Connecting to the fastest server, attempts to load that and than the message comes up.
Any suggestions on how I fix this?
I have gotten this before whenever I switch between characters too fast. Usually I just restart my computer and than it's resolved.
This however, I was not playing before hand. I have restarted my computer twice, no luck.

Try these guides to reset you IP address

Realm Down & Temp Ban Reversal Guide
Tiffiter's Unabridged Guide To Bypassing a Temp IP Ban

This guide has fixed that several times & helps allot with connection issue's

How to fix your D2 Connection Issue