we have an internal web site that requieres you to logon
most locations within the company it worsk fine but at several branch offices we just aget a 403 "This website requires you to log in error rather than an actual logon box so you can login
works localy at the location where web sit is and a few remote sites but very spasmodic.
every thing pings well and dns is all correct. we do use proxy servers (bordermanager) but occurs when this is bypassed too.