This is somewhat off topic but I am hoping that our ISA may help me identify this problem in some way. In the IP addresses that have been assigned to my network via DHCP is one that has a very strange MAC address. I have been unable to identify it. I have checked all equipment (PC's, router, server, printers) and cannot seem to locate it. Has anyone ever seen anything like this? 52:41:53:20:80:a2:d2:c5:99:bb:c0:01:01:00:00:00 This is the MAC address listed in the DHCP server. All of the others that the DHCP server has assigned addresses to have normal MAC address this one is strange. Did intrusion detection miss something? Ping requests time out to the address that the DHCP server has assigned to this MAC and yet, when I release that address "it" requests and receives another one almost immediately. Amy Babinchak Technology Consultant