Google crawling my site with 4 different ips

Why?

[akmac]

This may be common to some, but usually when I see googlebot on my site, there's only one ip. Right now, I'm seeing 4 online:

00:00:00 googlebot 66.249.64.28
00:02:41 googlebot 66.249.71.70
00:00:00 googlebot 66.249.71.28
00:00:00 googlebot 66.249.71.39

Any one know why this might be?

[Dijkgraaf]

Yes it is very common, what is unusual is that you were only seeing one. Probably because they have a number of machines that are doing the spidering rather than just the one.