I have about 100 ipads that pick up a dhcp address from our smoothwall. I have given them all a statically assigned address by ticking them and selecting the "add static from arp table" button on the dhcp server page. I then added the IP address to a location in guardian that is then used in an Ident by location authentication rule. All has seemed well for month. Since Christmas I have had a steady stream of ipad users come to be with ipads showing the smoothwall login page. Under investigation im finding that they are being issued with new address not related to the static assignment originally given. Having had a look on the dhcp server page of the smoothwall ip addresses under the heading "Current static assignments" are given a mac address. But I can find the same ip address in the "Add static assignment from ARP table " table relating to a different MAC address, and I can guarantee that i'll be seeing one or the other of these ipads in the next day or so either with a smoothwall login page are the wifi not connecting at all.

Example: ip address in the Current static assignment table should releate to mac address f4:f9:51:64:8b:6e


but I can also find ip address on the lower part of that page in the table headed "add static assignment from ARP table" relating to a totally different MAC address f4:f9:51:4d:cc:37:

new static.PNG

Am I doing something wrong or are my expectation wrong here? or is the smoothwall not behaving?