DHCP Minimum Lease Duration

The Microsoft Windows NT DHCP Service has been designed to allow a network administrator to assign a lease duration shorter than one hour for testing purposes. Always assign a lease duration longer than one hour for production systems in real work environments.

Section 3.3 of Internet RFC 1541 originally defined the minimum DHCP lease duration as one hour. RFC 2131 supersedes RFC 1541 and removes the minimum lease duration limit. However, for production systems, it is recommended that the minimum one-hour specification be adhered to.

It is typically not neccessary to change the DHCP scope lease time from its three-day default setting. If you think you need to change the default lease time, follow the recommendations below.

Reduce lease durations for DHCP scopes where high client turnover is found (for example, classroom or conference room environments where clients frequently come and go). DHCP scopes that are used for dial-up networking clients are another example.

Additionally, a DHCP Administrator may want to assign a shorter lease time to scopes with low ratios of availible addresses. Setting the lease time shorter in both these cases will increase the availiblity of addresses.

RFC1541 RFC2131