JSI Tip 0261 - Where does a DHCP client store lease information?

DHCP clients store information locally so that they can attempt to lease the same IP address and still function if the DHCP server is down.

A Windows NT client stores DHCP information in the registry at:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesParametersTcpip

A Windows 95 client also stores DHCP information in the registry at:

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesVxDDHCPDHCPInfo00

Windows for Workgroups with TCP/IP-32 stores the DHCP-related information in the DHCP.bin file in the subdirectory. This file is in binary format.

LAN Manager version 3.0 and LAN Manager for MS-DOS version 2.2c clients both store the local DHCP-related information in the DHCP.prm file in the directory. This file is in a binary format.