Windows Instance: Network Level Authentication Required

This document describes how to handle the alarm message Network Level Authentication Required when you connect to a Windows instance remotely.

Failure Symptoms

When you use the built-in remote desktop connection of the Windows system, sometimes there is a problem of being unable to connect to the remote computer, and a prompt Network Level Authentication Required appears.

Troubleshooting

Logging in to the CVM via VNC

1. Log in to the CVM console.
2. On the instance management page, find the target CVM instance and click Log In.
3. In the pop-up Log in to Windows Instance window, select Other methods (VNC) and click Log in now to log in to the CVM.
4. In the log-in window that pops up, select Send Remote Command in the upper left corner and click Ctrl-Alt-Delete to enter the system log-in interface.
   

Modifying the Registry

1. On the operating system interface, click , enter regedit, and press Enter to open the Registry Editor.
2. In the left sidebar, expand the directories in the following order:
   Computer > HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Control > Lsa, and find Security Packages in the right window.
   
3. Double-click Security Packages to open the Edit Multi-String dialog box.
4. In the Edit Multi-String dialog box, add the tspkg character and click OK.
   
5. In the left sidebar, expand the directories in the following order:
   Computer > HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Control > SecurityProviders, and find SecurityProviders in the right window.
   
6. Double-click SecurityProviders to open the Edit Multi-String dialog box.
7. Add , credssp.dll at the end of the Value Data in the Edit Multi-String dialog box, and click OK.
8. Close the registry editor, restart the instance, and you can log in remotely.