The lease period
is the amount of time that the DHCP client
can use an IP address
assigned by the DHCP server
To view the settings currently assigned to a client in WinNT, open a DOS window and type IPCONFIG /ALL. This will list the assigned IP addresses, the DHCP servers, the start of the lease periods and the end of the lease period. Instead of adding the /ALL switch, use /RELEASE to give up a lease or type /RENEW to renew a lease period.
When a client starts up, it automatically requests a renewal of the lease. If heard, the DHCP server will acknowledge. If the server cannot comply or the client has moved to a new domain, the DHCP server will send a NACK, or Not_Acknowledge, which forces the client to go through the DHCP lease process.