Sometimes when I hibernate or standby my windows XP box, starting it back up causes network failure. Websites couldn’t be found, ping failed, and ssh couldn’t go anywhere.
I was perplexed for a while, as restarting the wireless connection didn’t fix the problem. You actually had to restart the entire computer.
A few weeks ago I dug into the problem and realized the issue was the dns service.
To fix, just restart the dns service from a cmd window (as an administrator) like so:
net stop dnscache
net start dnscache
You should be good to go.