Google App Engine: Public IP Address Subnets for white listing

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

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.

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.

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