Network Level Authentication

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Network Level Authentication is a technology used in Remote Desktop Services (RDP Server) or Remote Desktop Connection (RDP Client) that requires the connecting user to authenticate themselves before a session is established with the server. Originally, if you opened an RDP (remote desktop) session to a server it would load the login screen from the server for you. This would use up resources on the server, and was a potential area for denial of service attacks. NLA delegates the user's credentials from the client through a client side Security Support Provider and prompts the user to authenticate before establishing a session on the server.

Network Level Authentication was introduced in RDP 6.0 and supported initially in Windows Vista. It uses the new Security Support Provider, CredSSP, which is available through SSPI in Windows Vista. With Windows XP Service Pack 3, CredSSP was introduced on that platform and the included RDP 6.1 Client supports NLA; however CredSSP must be enabled in the registry first.[1]


The advantages of Network Level Authentication are:


  • No support for other credential providers
  • To use Network Level Authentication in Remote Desktop Services, the client must be running Windows XP SP3 or later, and the host must be running Windows Vista or later [2] or Windows Server 2008 or later.
  • Support for RDP Servers requiring Network Level Authentication needs to be configured via registry keys for use on Windows XP SP3.
  • Not possible change password via CredSSP. This is a problem when "User must change password at next logon" is enabled or if an account's password expires.
  • Requires "Access this computer from the network" privilege, which may be restricted for other reasons.


External links[edit]