Using the /etc/hosts File for Name Resolution
When you configure the hostname resolution in the /etc/nsswitch.conf file for HA hosts, the key word files must
appear first in the "hosts line," because:
It is more reliable to use the /etc/hosts file
for hostname resolution
than it is to use DNS or NIS or both.
An HA Screen in the passive mode cannot send packets over
the network; therefore, remote hostname resolution, such as DNS or NIS, will
fail for passive HA Screens.