hwIpSessUserNameIP selects which occurrence (none, first, second, third, or fourth) of the user's IP address to include when constructing an IP-Session user's derived username. Admins use this to control whether and how the client's IP address is embedded into the auto-generated username used for authentication or accounting. For example, an admin wanting usernames that clearly incorporate the client IP for RADIUS accounting would set this to first(2) so the IP is included as the leading component.