When vasd is unable to contact the KDC or the Active Directory server, it reverts to disconnected mode. While in disconnected mode all NSS and PAM requests are resolved from the cache. Authentication Services can enter disconnected mode for one or more of the following reasons:
1 - The computer object has been deleted. If the hosts computer object has been deleted then vasd can no longer communicate with Active Directory because it cannot authenticate. The solution to this problem is to recreate the computer object, then restart vasd.
2 - The /etc/opt/quest/vas/host.keytab file is missing or invalid. If /etc/opt/quest/vas/host.keytab is deleted or becomes corrupt then vasd is no longer able to communicate with Active Directory because it does not have credentials to authenticate as the computer. The solution to this problem is to delete then recreate the computer and restart vasd.
3 - The computer is physically disconnected from the network or the network is down.
4 - The Active Directory domain controller server is down.