DHCP Minimum Lease Duration

• Microsoft Windows NT Workstation versions 3.5, 3.51, and 4.0
• Microsoft Windows NT Server versions 3.5, 3.51, and 4.0
• Microsoft LAN Manager version 2.2c
• Microsoft TCP/IP-32 for Windows for Workgroups, versions 3.11, 3.11a, and 3.11b
• Microsoft Windows 95
• Microsoft Network Client version 2.0 and 3.0 for MS-DOS

SUMMARY

Section 3.3 of Internet IETF's RFC 1541 (in Standards Track) has defined the minimum lease duration as one hour. Microsoft Windows NT DHCP Service Scheme has been designed to allow a network administrator to assign a lease duration shorter than one hour for testing purposes. For production systems, the minimum one hour specification should be abided by.

MORE INFORMATION

If a network that has had many changes occur and has had a high ratio between connected computers and available IP addresses, a DHCP Administrator may want to assign a shorter lease time to clients. The more changes that occur, and the higher the ratio, the shorter a lease needs to be.

But, if using a DHCP lease duration of less than one hour, the DHCP system may function irregularly. A lease duration of less than one hour might cause a DHCP server to have unexpected behavior in responding to lease renewal and binding. The error may not occur 100 percent of the time.

WORKAROUND

Always assign a lease duration longer than one hour for production systems in real work environments.