We have an ongoing but intermittent problem affecting our Area Offices.
The problem can appear and dissapear without any obvious cause or resolution.
The symptoms are, when people in our Area offices (over a WAN,) using Internet Explorer, open an intranet site, they get 407 Proxy Authentication Required. I can remove all proxy settings and still get this, if however I have the proxy settings set and I untick "Bypass Proxy For Local Servers" then the page loads. But we should be able to bypass the proxy for these internal sites.
Seems to mainly occur when pages are accessed by an alias, or when opening a link from one intranet site where the link is opening a page on another server.
Here in Head Office on the LAN we dont have this issue at all. It seems to affect only WAN sites and then the problem can be at one site, come good then days later another site will experience this.
It may be unrelated, but there are some external commercial websites that also return errors like "User" NULL" when they try and log in from the Area office sites as well, it is like the authentication information is being stripped away.
Any assistance on how to troubleshoot this or if anyone has seen this kind of behaviour before and can advise, it would be greatly appreciated.
Thanks.