What IP addresses are used by Google bots? Can we get a list of it?

Question

We are adding a region selection pop up on the landing page for the user to select the region before they are allowed to browse the site. Region selection is mandatory and users will not be allowed to browse the site until a region is selected.
Due to this, we foresee an issue with the bots crawling our website(https://www.westpharma.com/). We would like to get your inputs on how the Google bot crawling will be affected because of this pop-up and how we can handle this.
Do you have a fixed set of IPs or user agent names that we can use to bypass the pop-up?
Could you also provide your suggestions on the steps that we need to take so that bot crawling is not blocked on our site once the region selection popup is implemented.

RT2 · Accepted Answer

Here's an answer from @Dwsmart that will help
 
Google don't list the IPs they crawl from, there's many and they probably change often.
 
See the guidance for validating if an IP is a genuine googlebot: https://support.google.com/webmasters/answer/80553 (You'll need to use Reverse DNS).
 
I'd perhaps be more worried why you are geoblocking stuff from the US (nearly all googlebot requests come from the states) as EU ones perhaps, sounds like your detection is off.