Found it: Designing AirPort Networks 10.5 Windows (Manual) Chapter 3 Airport Network Design
Logging
You can set up your wireless device to log status information to the Mac OS X system log or the Syslog application on a Windows computer. This is helpful for understanding problems and monitoring a device’s performance.
To set up logging:
1 Open AirPort Utility, select your wireless device, and then choose Manual Setup from the Base Station menu, or double-click the device icon to open its configuration in a separate window. Enter the password if necessary.
2 Click the Advanced button, and then click Logging and SNMP.
3 Enter the IP address of the computer that will receive the logs in the Syslog Destination Address field.
4 Choose a level from the Syslog Level pop-up menu. You need to assign a Network Time Protocol (NTP) server for each wireless device, so the log information will contain the accurate time of the status logs.
To set the time automatically:
1 Open AirPort Utility, select your wireless device, and then choose Manual Setup from the Base Station menu, or double-click the device icon to open its configuration in a separate window. Enter the password if necessary.
2 Click the AirPort button, and then click Base Station.
3 Select the “Set time automatically” checkbox, and then choose an NTP server from the pop-up menu if you have access to one on your network or on the Internet.
If you click “Logs and Statistics” you can view and export logs, and view wireless client and DHCP client information.
If you export the logs, use the Mac OS X Console application, located in the Utilities folder in the Applications folder on a Mac, or in Start > All Programs > AirPort on a Windows computer, to view the logs on the computer receiving them.