What does Google use 173.194.90.xxx IP's for? Why is it not a googlebot.com pointer?

Question

I've been noticing this new Google range hitting our feeds over the last couple weeks. It's bordering on abusing our resources with multiple hits in short timeframe. The 173.194.90.xxx IP's fall under the Google ASN but it still seems phishy. Reverse DNS doesn't resolve (NXDOMAIN), and the user agent is simply [Googlebot]. A friend suggested it was a pub DNS exit IP, but I can't tell.

Has anyone else got hits from this range? Is this a legit Googlebot? Since it hits feeds/maps, perhaps it has something to do with feed quality checking?

EDIT: in addition to the above mentioned range, there is also 74.125.72.xxx range acting the same way on feeds.

Answer 1

Yes this is within the Googlebot ranges. Here is my list based upon past accesses. Please forgive the crude wildcards.

64.233.160.*
64.233.161.*
64.233.162.*
64.233.163.*
64.233.164.*
64.233.165.*
64.233.166.*
64.233.167.*
64.233.168.*
64.233.169.*
64.233.170.*
64.233.171.*
64.233.172.*
64.233.173.*
64.233.174.*
64.233.175.*
64.233.176.*
64.233.177.*
64.233.178.*
64.233.179.*
64.233.180.*
64.233.181.*
64.233.182.*
64.233.183.*
64.233.184.*
64.233.185.*
64.233.186.*
64.233.187.*
64.233.188.*
64.233.189.*
64.233.190.*
64.233.191.*
66.249.64.*
66.249.65.*
66.249.66.*
66.249.67.*
66.249.68.*
66.249.69.*
66.249.70.*
66.249.71.*
66.249.72.*
66.249.73.*
66.249.74.*
66.249.75.*
66.249.76.*
66.249.77.*
66.249.78.*
66.249.79.*
66.249.80.*
66.249.82.*
66.249.83.*
66.249.84.*
66.249.85.*
66.249.86.*
66.249.87.*
66.249.88.*
66.249.89.*
66.249.90.*
66.249.91.*
66.249.92.*
66.249.93.*
66.249.94.*
66.249.95.*
74.125.*
173.194.*

The following ranges have been used for other Google search related bots which still may be the case. However, it is also part of the Google e-mail services they provide to web sites and used for web hosting.

209.85.128.*
209.85.129.*
209.85.130.*
209.85.131.*
209.85.132.*
209.85.133.*
209.85.134.*
209.85.135.*
209.85.136.*
209.85.137.*
209.85.138.*
209.85.139.*
209.85.140.*
209.85.141.*
209.85.142.*
209.85.143.*
209.85.144.*
209.85.145.*
209.85.146.*
209.85.147.*
209.85.148.*
209.85.149.*
209.85.150.*
209.85.151.*
209.85.152.*
209.85.153.*
209.85.154.*
209.85.155.*
209.85.156.*
209.85.157.*
209.85.158.*
209.85.159.*
209.85.160.*
209.85.161.*
209.85.162.*
209.85.163.*
209.85.164.*
209.85.165.*
209.85.166.*
209.85.167.*
209.85.168.*
209.85.169.*
209.85.170.*
209.85.171.*
209.85.172.*
209.85.173.*
209.85.174.*
209.85.175.*
209.85.176.*
209.85.177.*
209.85.178.*
209.85.179.*
209.85.180.*
209.85.181.*
209.85.182.*
209.85.183.*
209.85.184.*
209.85.185.*
209.85.186.*
209.85.187.*
209.85.188.*
209.85.189.*
209.85.190.*
209.85.191.*
209.85.192.*
209.85.193.*
209.85.194.*
209.85.195.*
209.85.196.*
209.85.197.*
209.85.198.*
209.85.199.*
209.85.200.*
209.85.201.*
209.85.202.*
209.85.203.*
209.85.204.*
209.85.205.*
209.85.206.*
209.85.207.*
209.85.208.*
209.85.209.*
209.85.210.*
209.85.211.*
209.85.212.*
209.85.213.*
209.85.214.*
209.85.215.*
209.85.216.*
209.85.217.*
209.85.218.*
209.85.219.*
209.85.220.*
209.85.221.*
209.85.222.*
209.85.223.*
209.85.224.*
209.85.225.*
209.85.226.*
209.85.227.*
209.85.228.*
209.85.229.*
209.85.230.*
209.85.231.*
209.85.232.*
209.85.233.*
209.85.234.*
209.85.235.*
209.85.236.*
209.85.237.*
209.85.238.*
209.85.239.*
209.85.240.*
209.85.241.*
209.85.242.*
209.85.243.*
209.85.244.*
209.85.245.*
209.85.246.*
209.85.247.*
209.85.248.*
209.85.249.*
209.85.250.*
209.85.251.*
209.85.252.*
209.85.253.*
209.85.254.*
209.85.255.*

The following ranges have also been used for Google search bot activity in the past but not likely recently. However, this range does appear to be for web hosting.

216.239.32.*
216.239.33.*
216.239.34.*
216.239.35.*
216.239.36.*
216.239.37.*
216.239.38.*
216.239.39.*
216.239.40.*
216.239.41.*
216.239.42.*
216.239.43.*
216.239.44.*
216.239.45.*
216.239.46.*
216.239.47.*
216.239.48.*
216.239.49.*
216.239.50.*
216.239.51.*
216.239.52.*
216.239.53.*
216.239.54.*
216.239.55.*
216.239.56.*
216.239.57.*
216.239.58.*
216.239.59.*
216.239.60.*
216.239.61.*
216.239.62.*
216.239.63.*

It is unfortunate that Google has decided to be so dynamic with their IP addresses. They are confusing the security world. Their solution is to reverse the IP address to a domain name to ensure that any bot is from Google. But most web servers do not have that option available natively. As well, not all of the Google IP addresses reverse to a domain name. I do have to trim my list. It is hand generated from my database. I hope this helps.