by genie » Oct 25 05 2:06 pm
In DHCP properties click on DHCP settings page, edit the scope that contains the IP addresses that are being allocated to your clients, then change the lease duration.
Most clients will re-check with the DHCP server whenever they are rebooted, or whenever their LAN adapter is disabled then enabled.
Having said that, no guarantee can be given that the clients would use different IPs - if DHCP server receives a request from the client it has already served it will allocate the same IP address if it is available. Do you have a lot more machines than available IP addressess?