We have a few vlans and use two DHCP Servers running on Windows 2003 Server. We use IP helpers on our routers to forward IP packets to the DHCP Servers. I have implemented the Microsoft 80/20 rule as per the Microsoft best practice document. However I am having problems. I am getting leases in both the scopes for both my Windows XP clients and HP JetDirect Printers. Having read the technical data on DHCP it appears that if a Device attempts to renew it's address (either at T1, T2 or rebinding) it will contact the issuing DHCP server directly using Unicast, but if the Windows XP device is switch off then at start-up the DHCP client will broadcast which then has a 50/50 chance of having a lease on both DHCP Servers. How can Microsoft recommend this solution when it is clearly flawed? If I am missing a trick then I would love to know what.