The issue has been ongoing for maybe a year, which I believe is about the time that QIP was replaced with InfoBlox. The issue is that the clients prematurely give up their IP addresses and ask for a new one, which the DHCP server hands out but the client doesn't use. The client eventually (maybe within an hour) recovers on its own and may not have any more issues for several weeks, or it may have trouble again within 24 hours. When I looked at the IOS switch port, there was no MAC address for the affected clients. Anyone seen this issue?