IE 7 starts a new connection for every request when access one specific site

After upgrading from IIS 5 to IIS 6, client observed the web application performance was not as good as before. This site uses Windows Integrated Authentication, by compare the IIS log, customer found huge number of 401s were recorded in IIS 6 log. And each 401 takes about 300+ms since customer’s network has high latency….


Missing INTERNET_STATUS_REQUEST_COMPLETE callback after calling Wininet’s FtpOpenFile() in asynchronous mode

Symptom:   To reproduce the issue: 1.       Put a zero byte file on a FTP site. 2.       Call InternetOpen() with flag INTERNET_FLAG_ASYNC 3.       FtpOpenFile() to download the file. Wininet will send out a FTP request. After receiving the response, the registered callback procedure will receive an INTERNET_STATUS_REQUEST_COMPLETE event. 4.       Call FtpOpenFile() again. This time Wininet…


How to determine Cipher Suite between IE and IIS

  Assume you already looked at Xin’s article about How to use 256 bit SSL in IIS 6.0.   It is quite common to ask whether old version IE client will be affected after applying kb948963 which adds support for AES cipher suites in the Schannel.dll module for Windows Server 2003.   The answer is…


High Performance ASP.NET application (1) – Optimizing state management

Today we’ll talk a little about how to optimize state management when coding your ASP.NET application. I believe most of ASP.NET developers more or less have some knowledge of using state in ASP.NET. In this article, we’ll not be focusing on how to use state in ASP.NET but how to more efficiently and effectively manage…


Some perl clients get error message after upgrading FTP server from IIS 6 to 7

Symptom:   FTP client get below error   425-Cannot open data connection.  Win32 error:   The network connection was aborted by the local system.  Error details: Client IP on the control channel didn’t match the client IP on the data channel.   Troubleshooting:   1.       We followed the steps in to test opening FTP passive…