JSI Tip 1118. How do I force DHCP lease renewal?

When you remove a scope in DHCP manager and define another one, Microsoft DHCP clients will not automatically renew their lease.

To force lease renewal:

1. If you have W95 clients, you must copy Ipconfig.exe from WFW 3.11 to C:\WINDOWS, prior to running the script.

NOTE: If you have Winipcfg.exe version 4.10.1656 or later, you don't need to get Ipconfig.exe.

2. Add the following code to your logon script:

if /i "%OS%"=="Windows_NT" goto IPCFG
if EXIST C:\WINDOWS\IPCONFIG.EXE goto IPCFG
if EXIST C:\WINDOWS\WINIPCFG.EXE goto W98
goto IPCFG
:W98
C:\WINDOWS\WINIPCFG.EXE /RENEW_ALL
goto end
:IPCFG
IPCONFIG.EXE /RENEW
:end