The default domain IP ranges used by Google APIs and services are allocated dynamically and change often. To get an accurate list, refer to these two lists that Google publishes and updates frequently:

• IP ranges that Google makes available to users on the internet
• Global and regional external IP address ranges for customers' Google Cloud resources

To obtain the net list of default domain IP ranges, subtract the ranges in the second list from the ranges in the first list.

For a Python script that will automate this process, see IP addresses for default domains.

• Configuring Private Google Access
• Google IP address ranges for outbound mail servers
• Hostname allowlist for all Chrome devices
• Set up a Google Workspace host name allowlist