The display manager must authenticate itself to the server. To do this the X server sends a codice_5 packet to the display manager, which returns an codice_6 packet. If the codice_6 packet contains the response the X server expects, the display manager is authenticated. Producing the correct response might require the display manager to have access to a secret key, for example. If authentication succeeds, the X server sends a codice_8 packet to inform the display manager. Then the display manager displays its login screen by connecting to the X server as a regular X client.