Exceptions during a HTTP post using WebClient

From: john (johnwww_at_hotmail.com)
Date: 06/18/03

Date: Wed, 18 Jun 2003 05:49:34 -0700


i have to request an ASP page from my machine.
So, i use webclient and UploadData for the HTTP request.
I specify a credential for the webClient object because
the site is setup with NTLM authentification :

NetworkCredential vo_cre = new NetworkCredential
(user ,pwd,domain);
web = new WebClient ();
web.Credentials = vo_cre ;
web. UploadData(myurl,"POST",mydata);

Sometimes, a WebException is thrown :

NameResolutionFailure or ConnectFailure.

What could be the causes of these exceptions ?