I am running a Windows 2003 R2 server that is also my DHCP server. I have about 53 Windows workstations that use 1 subnet in a non-routed network. The DHCP lease time for the subnet is 8 days. I see in the DHCP MMC that the lease was assigned for a particular address and the expiration time is 8 days at a certain hour. I have confirmed the lease time by looking at the workstation's registry. According to my understanding of how DHCP works, I should not see any broadcasts for this workstation for 4 days. However, I am seeing frequent DHCP broadcasts, not to the DHCP server, but to the broadcast address of 255.255.255.255 port 67. The workstations only have one network card.
What could be causing the extra broadcasts?