The reason for the authentication window is simple: Internet Explorer sends your credentials only if it believes that the host is in the Local Intranet zone (assumed to be the default). If the host outside of what IE considers “local” is requesting NTLM credentials, an authentication window will appear and you must authenticate manually.
If you want your credentials to be sent automatically, make sure IE thinks about it in the "Local Intranet". Check the zone information far to the right in the status bar to see the current active zone.
IE takes into account a lot of things to decide whether to consider a host as a "local intranet":
- is the IP address on the local subnet → YES
- this is a simple host name (ie "no dots") -> YES
- in IE settings: is it in the "Sites ..." list for "Local Intranet" → YES
- in IE options: is it in the proxy exception list → YES
- is the UNC path -> YES
- otherwise: NO
- Sometimes in the list of personal passwords for this host name there is an old password (accessible through the Control Panel → User Accounts). If this is not the case, similar problems may occur.
My suspicion is that your host "fred" does not fulfill condition number 2 to number 4, but your test case "Betty" somehow does.
How the name was resolved (CName record, record, hosts file, etc.) does not matter, because the name resolution method is not transparent to the calling application. IE just asks for the name "XYZ" and returns the IP address.
However, recent configuration changes may require you to clear the local DNS cache. Random ipconfig /flushdns may help ipconfig /flushdns , alternatively you can temporarily stop the DNS client service.
The described internal logic is applied to the host name and security settings changes depending on the result.
Tomalak
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