HTTP/1.1 specifies that by default persistent connections should be used. I'm wondering if the ASP.NET Web Development Server supports them. So far I have seen that even though an HTTP request contained
Connection: Keep-Alive
header the response contained
Connection: close
which forces the browser to close the connection after request rather then use pipelining.
It's not a big issue, but there is one interesting drawback which is the fact that the browser does DNS lookup before each request which add to the page load time significantly.
It's best seen in Firebug (in the "net" tab).
As per the link below Cassini doesn't support persistent connections. It will always return Connection: Close
Reusing Connections