Digest Authentication
dsa.msc
NTLM
DHCP
SASL stands for Simple Authentication and Security Layer. It is a framework for authentication within Internet protocols, allowing for secure authentication mechanisms to be used during communication between clients and servers.
Kerberos
AllowOverride
Applegate Directory provides business to business solutions. They are mainly for networking in the United Kingdom and Ireland. The directory provides information on more than 250,000 clients and customers.
By using a webpage-based business directory a person or company can improve their levels of advertising. This may help them to reach new clients and contacts.
SRV records. SRV Records are the locator records withing DNS that allow clients to locate an Active Directory domain controller or global catalog.Source: Microsoft Windows Server 2008 Active Directory Configuration Official Academic Course Textbook.
Check settings for client connections, and check your firewall. Usually good servers have it.
You definitely need LDAP to mix Windows clients and Linux systems together since they do not share the same authentication technique. You can configure a Samba system to be a domain controller for Windows clients, which would give you the single-signon approach.
Network Level Authentication is used to authenticate Clients and servers to the network in Windows XP. It is also used to establish a remote desktop connection.