NOTE: FortiNAC is now named FortiNAC-F. For post-9.4 articles, see FortiNAC-F. FortiNAC is a zero-trust network access solution that provides users with enhanced visibility into the Internet of Things (IoT) devices on their enterprise networks.
Article Id 192719
Persistent Agent Credential Popup not appearing when isolated.  User unable to register Mac OSX machine.

In order for the Persistent Agent to prompt for credentials, the end station must be able to resolve localhost.  In order for resolution to occur, the /etc/hosts file on the Mac-OS-X end station must have an entry for localhost.

To verify if localhost resolves, type the following command in the terminal of the affected MAC OSX machine:
ping localhost

A reply from should appear if resolving properly.  If ping fails, then the localhost entry may be missing.

From the terminal of the affected MAC OSX machine, ensure the /etc/hosts file contains the localhost entry.   

Example of a correct /etc/hosts file:

# Host Database
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##    localhost    broadcasthost
::1             localhost

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