I have IPv6 disabled on my computer because it solves many mysterious service interruptions. Comcast claims to support it, but there have been many times when IPv6 was dog slow and IPv4 was very fast.
Comcast used to issue me an IPv6 block but silently stopped at some point. Others reported the same problem. Thankfully everything I use still supports IPv4 so I didn't notice until I went looking.
One day it'll be worth my time to figure out the problem, but I predict that day is far in the future.
