I just received an email from one of the virtual servers I manage - it was having trouble resolving a domain name. Its hosted by Linode and this was the first notification I've received like it.
I tried ssh'ing in without success, then tried a reboot, and shutdown but nothing was happening. I also tried using the Lish console, but that didn't work either. I created a ticket and got an immediate response saying they were experiencing network problems.
Thankfully, it appears the problems have been resolved fifteen minutes later.
ACK! Looks like I spoke too soon. My VPS is again unavailable. Grrr.
UPDATE: A little bit later they report the problem has been resolved and that it was a upstream routing issue.