Google App Engine - urlFetch address not in _netblocks.google.com

Question

For software I am developing, I need to have a list of external IP addresses that Google App Engine uses for urlFetch requests. Getting a complete list is proving difficult.

The accepted wisdom as detailed on SO is to use the output from...

dig -t txt _netblocks.google.com

...but unfortunately this list is incomplete. For example, my urlFetch requests currently emerge from unlisted addresses:

US based App: 8.35.201.x
EU based App: 8.35.200.x

Is there any way to get an actively updated list of external IP addresses used by urlFetch?

score 4 · Accepted Answer · answered Jul 18 '14 at 07:34

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The official advice is https://developers.google.com/appengine/kb/general#static-ip. Note that relying on Static IP addresses is bad, for all the reasons listed on that page.

answered Jul 18 '14 at 07:34

Nik

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Thanks for the link to new documentation, which was lacking at the time of the original post...and yes, IP filtering is highly sub-optimal; but if you have to integrate with a 3rd party system that implements it (unfortunately many still do), then you're forced down this route. This new doc definitely helps explain what you need to do to achieve this. – tsal Aug 14 '14 at 10:37

score 1 · Answer 2 · edited Jul 29 '13 at 15:24

1

So, the answer is:

dig txt _cloud-netblocks.googleusercontent.com +short
"v=spf1 include:_cloud-netblocks1.googleusercontent.com include:_cloud-netblocks2.googleusercontent.com include:_cloud-netblocks3.googleusercontent.com ?all"

edited Jul 29 '13 at 15:24

Attila O.

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answered Jun 06 '13 at 14:44

tsal

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Google App Engine - urlFetch address not in _netblocks.google.com

2 Answers2

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