Similar to this submission, I am looking to find out the IP addresses used by ArcGIS Online. We are preparing to make use of a few services there but our network security team won't add a firewall rule for everyone to access our internal resources and instead want to restrict the source IPs to those used by ArcGIS Online.
I have contacted Esri support as suggested in the linked post above but was told that there is no static IP addresses and have been given a list of domains to be excepted. This isn't going to work for our firewall rules, of course.
Does anyone know what ranges are used here, or is this not possible?