We received this question. I thought somebody else might need it, so posting it here.
Q. I need to get the IP addresses of the servers where my BIM 360 Field project is hosted. This is to open the correct range of IP addresses inside of the firewall. Is it possible to get them?
A. Field uses Amazon in the back end. The list of possible IP addresses is published by Amazon:
These EC2 IP ranges are also available in JSON format:
Field web servers are in the US West (Northern California) data center.
09/05/2016 – updated. Took out the link to the original announcement which has been deprecated.