Allow Non FQDN
Supported on: Firefox 62 or later, Firefox 60.2 ESR or later
Registry
HKLM
Software\Policies\Mozilla\Firefox\Authentication\AllowNonFQDN HKCU
Software\Policies\Mozilla\Firefox\Authentication\AllowNonFQDN Options
NTLM boolean SPNEGO boolean Description
If this policy is enabled (and the checkboxes are checked), you can always allow SPNEGO or NTLM on non FQDNs (fully qualified domain names). If this policy is disabled or not configured, NTLM and SPNEGO are not enabled on non FQDNs.