.Net Web Request - Unable to connect to the remote server

I'm using .Net Web Request to read the html of selected Webpages.

Once in a while I'm getting the following error:

2010-09-05 13:14:51,986 [File_29] ERROR Boxer.Classes.GetLinks [(null)] - HtmlUtils - GetResponse - Url - http://domain.com/index.html
System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 69.212.110.118:5068
   at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
   at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Int32 timeout, Exception& exception)
   --- End of inner exception stack trace ---
   at System.Net.HttpWebRequest.Get开发者_如何学编程Response()
   at Boxer.Classes.GetLinks.GetResponse(String url, Int32 timeout, Boolean& timeoutException)

I know for sure that the target URL is available.

Any idea what is the cause of the error?

There could be different reasons for this happening. Maybe the target server is throttling the response because it believes the request comes from a bot. In this case you might consider sending proper HTTP headers (if it works in your browser, try sending the same request headers). Also there could be a proxy in between that you need to configure and use.