Network monitoring has shown that many iPad devices have caused a problem on the campus network. These devices continue to use an IP address they have been leased well beyond the time they should. (In technical terms, the device's DHCP client software stops renewing its lease, but the device keeps using the IP address after the DHCP lease expires. This is not a WiFi issue.) This behavior causes a disruption on the campus network.
 
We believe this is a bug within the iPad/iPhone OS 3.2 software.
OIT has reported this bug to Apple. Princeton network administrators and Apple are working together to resolve the issue.

Until a fix is provided by Apple, OIT recommends that iPad owners use the
    Workaround for "iPad/iPhone OS 3.2 Stops Renewing DHCP Lease, Keeps Using IP Address" Issue
 

That temporary workaround may prevent the iPad from malfunctioning in this manner.
iPad devices that continue to malfunction while connected to the campus network may need to be blocked to maintain the stability and reliability of campus network services.

For detailed technical information regarding this issue, please see:

http://www.net.princeton.edu/announcements/ipad-iphoneos32-stops-renewing-lease-keeps-using-IP-address.html