JSI Tip 8965. When a program running on Windws XP SP2 connects to an IP address in the loopback range, it may not work as expected?

Starting with SP2 (Service Pack 2), the operating system prevents any connection to an IP addresses in the loopback range, except for 127.0.0.1.

To resolve this issue, Download the Update for Windows XP Service Pack 2 (KB884020) package.

NOTE: See the following Microsoft Knowledge Base Articles:

817293 - Remote Desktop Connection does not permit loopback connections to ports that it is not listening on.

314067 - How to troubleshoot TCP/IP connectivity with Windows XP.

Description of the Contents of a Windows Server 2003 Product Update Package.