Sometimes instances launch with more than one IP
Sometimes when I launch an instance it will show as having more than one IP. When I log in to the instance it only has one interface, eth0 (and lo) and there is only one IP address configured on it. The second IP address is nowhere to be found inside the instance, I only see it on the dashboard.
It seems like this becomes more common when launching multiple instances at the same time, but I have had it happen when launching a single instance too.
What could cause this? I can't find any error messages, presumably because the instance launched successfully.