I’ve noticed that this is somewhat unclear in the EZproxy documentation
ExcludeIP is a very cool function available in configuring your config.txt exproxy file that allows you to automatically bounce internal users to the database without going through EZproxy authentication.
If your local IT department has a specific range, use theirs. But if they are unresponsive when you ask about the internal range of IP addresses, the international standards are a good place to start
These three sets of ExcludeIP directives should cover all of your internal users.
ExcludeIP directives got at the end of your config.txt file.