Enabling External and Local Authentication Services
To make authentication function properly all the time - even when external authentication is not available, you can enable both the local and remote authentication services.
When both authentication services are enabled, the PXE follows these rules for authentication:
When any of the remote authentication servers in the access list is accessible, the PXE authenticates against the connected authentication server only.
When the connection to all remote authentication servers fails, the PXE allows authentication against the local database.