We have an Ethernet 10/100 switched network, using a DHCP server called haneWIN DHCP Server, ver. 3.0.20. We're using 192.168.1.### as our network address (with the DHCP server on 192.168.1.48). We have the DHCP address pool set to 200 - 240, which is plenty (most of our devices are statically addressed, in the 1 - 178 range). We have a laptop user (call him LAPTOP), who uses the same addressing scheme on his home network (even using the same gateway address). Every day, when he plugs his laptop onto the network and fires up his laptop, another user (call her WIRED) on the network gets a IP Conflict error:
EventID 4199 - The system detected an address conflict for IP address 192.168.1.91 with the system having network hardware address 00:15:C5:3C:E6:D7.
I have confirmed that this MAC address is LAPTOP's PC. And LAPTOP's owner assures me that he shuts down the machine at home, they re-starts it here at the office (it's not in standby or hibernation).
By the time I get to LAPTOP's PC, it has been assigned a valid DHCP address.
So I'm trying to figure out several things:
1. Since the error appears in WIRED's Event Logs, her OS must be detecting the error. But it only occurs once, and then (apparently) the DHCP server makes the new IP assignment, before whatever IP polling occurs a second time on WIRED's PC. Is there a setting to "hide" the message, or a timeout value which can help?
2. Is there a way to force LAPTOP's NIC to drop a leased IP # when LAPTOP's PC is shut down?