Redirected to Former Site After Web Resource IP Address Is Changed (297086)

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256986 Description of the Microsoft Windows Registry

SUMMARY

If the IP address of a Web resource that you access through a proxy server (or an array) is changed, you may be redirected to the former site by the Proxy DNS Cache until the Time To Live (TTL) value of the older, cached entry expires.

The default TTL for cached entries is 6 hours (21,600 seconds, hexadecimal: 0x5460). You can modify this value to a minimum of 1 hour by editing the registry.

MORE INFORMATION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

The following Registry values affect the Web Proxy service on Proxy Server.

To change the default TTL value:

Start Registry Editor (Regedt32.exe).
Locate the DnsTTLInSecs value under the following key in the registry:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W3Proxy\Parameters
On the Edit menu, click DWORD, type 0xe10, and then click OK.
Quit Registry Editor.

In hexadecimal, the full TTL range is

DnsTTLInSecs REG_DWORD 0xE10 - 0x8CA0

3,600 to 36,000 seconds respectively.

To clear the cache, stop all proxy services of array members, such as Web Proxy, Winsock Proxy, and Proxy Administrator. Delete the physical folders under the URLCACHE folder on each array member, and then restart the proxy services. Otherwise, you can create a cache filter that avoids caching the DNS named Web resource. After the DNS TTL expires for the cached objects, remove the filter. The filter is global to all array members.