DOCUMENT:Q227943 04-FEB-2000 [iis] TITLE :How IIS Handles Reverse Lookup Failures PRODUCT :Internet Information Server PROD/VER:winnt:4.0 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Internet Information Server 4.0 - Microsoft Internet Information Services version 5.0 ------------------------------------------------------------------------------- SYMPTOMS ======== IIS can perform access restrictions based on IP address, IP range, and DNS name. If you are performing IP restrictions based on the DNS name, it requires that IIS perform a reverse DNS lookup. If reverse DNS lookup fails (for example failure to access the DNS server) then the request is refused. MORE INFORMATION ================ Note: You may need to restart IIS in some instances if the reason for the lookup failure is corrupted DNS entries. Additional query words: ====================================================================== Keywords : Technology : kbiisSearch kbiis500 kbiis400 Version : winnt:4.0 Issue type : kbprb Solution Type : kbpending ============================================================================= 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 2000.