I have a strange reoccurring problem. First some background on how we are setup. I have 6 4404 WLCs each licensed for 100 APs. They are all running version 18.104.22.168 configured the same using WCS version 22.214.171.124. Each have 7 WLANs defined. One of the WLANs is an open guest WLAN. We are NOT using anchor controllers for guest traffic; it simply is defined to a guest VLAN interface that routes through a virtual interface on our ASA5520. We do allow DHCP traffic through the ASA to our enterprise DHCP server. The guest WLAN is configured to require DHCP address assignment. All works fine for the most part and has been for over a year. The problem is that about every 30 days or so we will have a report of some guests not able to get an IP address. I will look at WCS and find that on one controller everyone connected to guest has an IP address of 0.0.0.0 and their Policy Manager State is at DHCP_REQ. If I reboot that controller all is fine for another 30 days or so. This only happens on two of my six controllers. By the way, I need to run version 5 due to an application that requires the ability to use WorkGroup Bridges. Thanks for taking the time to think about this!!!