Google IP address range for whitelist

Question

We are creating a captive-portal setup where we will like to allow unauthenticated access to all google services.

To achieve this we will have to get the list of IP addresses google uses and then whitelist them. I understand I will have to run a cronjob to keep the list updated but is there any way (API or otherwise) I can reliably get that list.

Answer 1

Why not allow based on DNS, then you don't need to keep track of all the IPs...

Here's our whitelist...

`
^(.*\.)?gmail\.com$
^(.*\.)?gmailblog\.blogspot\.com$
^(.*\.)?google\.com$
^(.*\.)?googleapis\.com$
^(.*\.)?googleblog\.blogspot\.com$
^(.*\.)?googledrive\.com$
^(.*\.)?googleenterprise\.blogspot\.com$
^(.*\.)?googleonlinesecurity\.blogspot\.com$
^(.*\.)?google-opensource\.blogspot\.com$
^(.*\.)?googlevoiceblog\.blogspot\.com$
^(.*\.)?googleusercontent\.com$
^(.*\.)?google-analytics\.com$
^(.*\.)?googlecode\.com$
^goo\.gl$
`