Google App Engine: Public IP Address Subnets for white listing

Question

Does anyone know if there is a set of IP addresses/subnets that GAE uses to serve up content/issue requests? I have an app that needs to fetch a url from another service. That service will only work if the fetch is from a whitelisted IP address. Hence the question.

Thanks! Rhett

Answer 1

For Google Postini services: http://www.google.com/support/appsecurity/bin/answer.py?answer=141669

Also I compiled this addresses from years of pinging :-) and various forums. Can't guarantee thou that the list is accurate, can't find any official Google info on it other than that Google Postini link.

64.68.82.1 - 64.68.82.80

64.208.33.33

64.209.181.52

64.209.181.53

209.185.108.134 - 209.185.108.165

209.185.253.167 - 209.185.253.188

It's hard to say which ones you need exactly as the app will connect to the closest google's data center, and there at least 6 ones in US alone that I know of. I'm sure there are plenty more.

Answer 2

Outgoing requests such as URLFetch will always be made from addresses in the list that _netblocks.google.com's TXT record resolves to. Incoming requests could go to any address that ghs.google.com resolves to anywhere in the world - but since the address resolution is location-dependent, there's no practical way to get a complete list.

Note that in either case, addresses will change over time, so you should not resolve them once and expect that list to remain accurate indefinitely.

Answer 3

OK, this seems to be the answer--if anyone wants to chime in with a confirmation, let me know. From http://groups.google.com/group/google-appengine/browse_thread/thread/d1e592a4a535378a/318ffadfb5d6c949?lnk=gst&q=ip+address#318ffadfb5d6c949

URLFetch should use these blocks:

$ dig _netblocks.google.com TXT