I will show you how you can identify the version of a Web server by issuing telnet command.
In the following example, we want to determine the version of a Web server by issuing a Hypertext Transfer Protocol (HTTP) HEAD request. The HEAD method allows a client to request HTTP header information. The output from the HEAD request will help us identify important information about the server, including the type and version of the Web server that is running. To perform a HEAD request, we’ll need to make a connection to the target Web server using the telnet command:
telnet www.microsoft.com 80
This simply makes a TCP connection to the Web server. Once the connection established, you need to issue the following command into the telnet Window:
HEAD / HTTP/1.0 After you hit enter two times, we get the following response (http header information) from the Web server. HTTP/1.1 200 OK Cache-Control: no-cache Content-Length: 1020 Content-Type: text/html Last-Modified: Mon, 16 Mar 2009 20:35:26 GMT Accept-Ranges: bytes ETag: "67991fbd76a6c91:0" Server: Microsoft-IIS/7.5 X-Powered-By: ASP.NET Date: Fri, 10 Jul 2009 12:33:15 GMT Connection: keep-alive
As you can see from the results , www.microsoft.com is surprisingly running a Microsoft-IIS/7.5 Web server using the ASP.NET Web application framework.
