If the DHCP server does not have IP addresses available to provide to the Bootstrap Protocol (BOOTP) service for its clients, BOOTP fails. When this occurs, consider the following possible solutions:
Use scope extension to expand the address range for the current scope.
Reduce the lease duration and decrease the cleanup interval. This can help tospeed the reclaiming of expired scope IP addresses.
Extend the DHCP scope
If you already have a DHCP scope and the Start Address and End Address do not currently include all addresses for yourspecific subnet, you can increase the number of addresses in the scope by extending the Start Address or End Address in the scope properties.
To increase the number of addresses available to clients:
At the DHCP server, click Start, point to Administrative Tools, and then click DHCP.
In the console tree, right-click the scope you want to extend, and then click Properties.
Change Start IP Address and End IP Address to extend the scope.
Reduce the lease duration
To perform these procedures, you must be a member of the Administrators group, or you must have been delegated the appropriate authority.
Toreduce the lease duration:
In the DCHP console tree, right-click the scope you want to configure, and then click Properties.
On the General tab, under Lease duration for DHCP clients, type the new lease duration.
Decreasethe cleanup interval
To use a Netsh command to set the cleanup interval time:
At the DHCP server, click Start, click Run, type cmd, and then press ENTER.
netsh dhcp set databasecleanupinterval "NewInterval"
(where "NewInterval" is the amount of time in minutes between DHCP database cleanups).
In the following example, this command sets the database cleanup interval to 10,080 minutes (every seven days).
netsh dhcp set databasecleanupinterval 10080