Several colleges, including Cornell and Princeton, have banned the Apple iPad from connecting to the college networks until Apple can apply a fix. It seems that the connectivity issues involves the iPad not releasing an IP address even when the lease has expired and the device is assumed by the owner to have disconnected. It is because the device does not disconnect that the college networks are concerned since the same IP could be leased to another device.
In an official explanation Princeton states the follow:
When a DHCP client malfunctions this way repeatedly, Princeton blocks the device from using those campus network services which rely on the device’s DHCP client respecting lease times. These include our wireless services. We do this to protect other customers of those services from the disruptions caused by the malfunctioning devices.
Within a few days of the iPad’s arrival, we had seen enough incidents from those iPads already on campus to conclude that there was a problem. Roughly half the iPads atached to our network had malfunctioned in the same way; the symptoms all matched the description above. Because the problems were so common and began as soon as the iPads arrived, we felt it unlikely that the problem was due to customer misconfiguration. It seemed more likely to be an issue common to the iPad/iPhone OS 3.2 platform. We collected technical data and reported the issue to Apple on April 7. Given the symptoms we have seen, we hope that it is due to some bug in iPhone OS 3.2 and can be addressed via a software update.
Since then, we’ve found that we can reliably reproduce the problem by allowing the iPad to lock its screen before DHCP lease renewal time, and then allowing it remain in its “locked screen” state until the DHCP lease has expired. (This assumes the iPad experiences no 802.11 wireless disconnect/reconnect events during that time.) Detailed steps to reproduce the problem appear below.
Some media reports have concluded that Princeton discovered (or diagnosed) a WiFi issue with the iPad, sometimes reporting that the issue Princeton has seen is the cause of iPad WiFi signal issues or connectivity issues others may have described. This conclusion is inaccurate; the issue Princeton has seen is a DHCP client issue. We have not experienced (or diagnosed) a WiFi signal or connectivity issue with the iPad.
But this situation may also be affecting home users as well, according to another report:
As we reported earlier this month, quite a few iPad owners have experienced WiFi connectivity issues with their devices. There seems to be a wide variety of issues, ranging from bad WiFi reception to regular drops on the WiFi connection because of what looks to be a bug in how the iPad connects to some routers.
But there is good news. It seems that Apple will be able to fix these problems with a simple upgrade.