WebClient作为本地系统运行时无法下载文件

Question

I have a windows service running as the default Local System (on Windows Server 2008 R2) that attempts to pull down a PDF from a user-provided URL. If that URL is in the local intranet there's a happy ending. If the URL points to a more remote URL (say from irs.gov), I get an exception:

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 ...

If I change the the "Logon as" account from Local System to my account (for instance), the request goes through. But I'm reluctant to run a windows service as a real user (am I being too conservative?).

The code I'm using seems pretty simple:

string destinationFileName = ...;
Uri uri = ...;
using (var wc = new WebClient()) {
    wc.DownloadFile(uri.AbsoluteUri, destinationFileName );
}

Do I need to get some kind of IE settings and add them to the WebClient instance? If so, what?

Thanks for any hints or pointers!

Answer 1

Try running your service with NT AUTHORITY\\NETWORK SERVICE. If that doesn't do the trick, Create a user account with appropriately restricted rights and run your service with that account.

Also, if you're running on Windows Server 2008 R2 give the Managed Service Accounts topic on Technet a look.

Answer 2

LocalSystem doesn't have access to network resources. Use NETWORK SERVICE account.

EDIT: LocalSystem most likely does not have write permissions to the filesystem path you are using.