DOCUMENT:Q271455 08-AUG-2001 [winnt] TITLE :Releasing a DHCP-Assigned IP Address at Shutdown in Windows NT PRODUCT :Microsoft Windows NT PROD/VER:winnt:3.1,3.5,3.51 (all service packs),4.0 OPER/SYS: KEYWORDS:kbnetwork kbtool ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server versions 3.1, 3.5, 3.51 (all service packs), 4.0 - Microsoft Windows NT Workstation versions 3.1, 3.5, 3.51 (all service packs), 4.0 ------------------------------------------------------------------------------- SUMMARY ======= There may be situations in which you want to have the IP address that was assigned to your computer by Dynamic Host Configuration Protocol (DHCP) automatically released when you shut down your Windows NT-based computer. There is no built-in functionality in Windows NT 3.x or 4.0 to automatically perform this task. MORE INFORMATION ================ For mobile users with laptop computers, Microsoft recommends using a hardware profile to eliminate any conflicts with the DHCP-assigned address that is bound to the local network adapter and the new DHCP-assigned address on the Point-to-Point Protocol (PPP) NDISWAN adapter for remote dial-up clients. However, there may be some situations in which a hardware profile may not accomplish this result (for example, if you have a docking-type laptop computer). When you are in the office, the DHCP-assigned address for the corporate network is bound to the network adapter in the docking station. When you travel to remote corporate sites, you may still want to have the ability to plug the laptop computer into a corporate Ethernet network connection. This requires an additional PC Card network adapter to be installed in the laptop computer. Rather than simply installing the PC Card network adapter, you can install a network adapter and modem combination PC Card. In this case, it may be difficult to configure a hardware profile that eliminates the PC Card network adapter that does not also eliminate the PC Card modem from the profile. In these types of situations, you need to release the DHCP-assigned IP address that is bound to the network adapter instead of eliminating the network adapter as a whole by using a hardware profile. In Microsoft Windows 95 and Microsoft Windows 98, there is a registry setting that you can use to release the IP address at shutdown. The registry value is named ReleaseLeaseOnShutdown. No such functionality exists for Windows NT. One possible method for releasing the IP address is to use the "ipconfig /release" command in a batch file, followed by the shutdown.exe command. Shutdown.exe is a Windows NT 4.0 Resource Kit utility. For additional information, click the article number below to view the article in the Microsoft Knowledge Base: Q158388 Useful Resource Kit Utilities for Domain Administrators Additional query words: ====================================================================== Keywords : kbnetwork kbtool Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTW310 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS350 kbWinNTS310 kbWinNTS350search kbWinNTS310search kbWinNT310Search kbWinNTW310Search Version : winnt:3.1,3.5,3.51 (all service packs),4.0 Issue type : kbinfo ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.