DOCUMENT:Q216091 TITLE :GetHostByName() Returns IP Address of Disabled Interface PRODUCT :Windows NT PROD/VER:4.0 OPER/SYS:WINDOWS NT KEYWORD :kbbug4.00 kbfix4.00 ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0 SP4 - Microsoft Windows NT Server, Enterprise Edition version 4.0 SP4 - Microsoft Windows NT Workstation version 4.0 SP4 ------------------------------------------------------------------------------- SYMPTOMS ======== In Windows NT 4.0, it is possible to set up multiple hardware profiles using the Devices tool in Control Panel. The device for the network interface card (NIC) can be disabled on a per-profile basis. In such a scenario, Sockets-based applications running on Windows NT 4.0 Service Pack 4 may fail unexpectedly. This problem has been observed in NetShow and Microsoft Exchange applications. The problem can also occur on multihomed computers where one of the NICs is disabled. CAUSE ===== This problem occurs because the GetHostByName() API returns the old IP address owned previously by the disabled NIC. RESOLUTION ========== A supported fix that corrects this problem is now available from Microsoft, but it has not been fully regression tested and should be applied only to systems experiencing this specific problem. If you are not severely affected by this specific problem, Microsoft recommends that you wait for the next Windows NT 4.0 service pack that contains this fix. To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web: http://support.microsoft.com/support/supportnet/default.asp The English version of this fix should have the following file attributes or later: Date Time Size File Name Platform ------------------------------------------------------------- 01/20/99 03:19p 43,280 Rnr20.dll (x86) 01/20/99 03:22p 71,440 Rnr20.dll (Alpha) This hotfix has been posted to the following Internet location as Rnr-fixi.exe (x86) and Rnr-fixa.exe (Alpha): ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/ hotfixes-postSP4/Rnr-fix/ NOTE: If this product was already installed on your computer when you purchased it from the Original Equipment Manufacturer (OEM) and you need this fix, please call the Pay Per Incident number listed on the above Web site. If you contact Microsoft to obtain this fix, a fee may be charged. This fee is refundable if it is determined that you only require the fix you requested. However, this fee is non-refundable if you request additional technical support, if your no-charge technical support period has expired, or if you are not eligible for standard no-charge technical support. For more information about eligibility for no-charge technical support, see the following article in the Microsoft Knowledge Base: Q154871 Determining If You Are Eligible for No-Charge Technical Support STATUS ====== Microsoft has confirmed this to be a problem in Windows NT 4.0 Service Pack 4. Additional query words: 4.00 sp4 ============================================================================ 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.