Thread:Project:Support desk/Auto Login to Mediawiki (Auth remoteuser Extension)/reply (13)

SSPI is the interface to access NTLM, among other security providers.

If the setting doesn't work, try without the protocol. If it still doesn't work, maybe you're using Kerberos authentication, in which case you would use the  instead of.

If it is working on localhost on Chrome and IE then there is nothing wrong with your settings (unless you want to have it also work on non-intranet sites, in which case you would need to enable automatic login on trusted sites and add those sites as trusted sites in the internet options, as well as to the manual Firefox setting).