Server-use changes normally go into effect whenever the client machine is rebooted or updates its cache manager.
When you use nisprefadm to set or change server preferences on a local machine using a local client_info file (the -L option), your changes go into effect immediately.
For machines obtaining their server preferences from a global client_info table (the -G option) you can force server preference changes into immediate effect by running nisprefadm a particular with the -F option.
# nisprefadm -F
For example, to force immediate implementation of changes to vega's preferred server list (whether local or global):
vega# nisprefadm -F
The -F option forces the machine's cache manager to immediately update its server preference information from the domain's global client_info table. If the machine on which you run nisprefadm -F has its own local client_info file in /var/nis, running this command will have no effect.
You cannot use the -F option with any other nisprefadm options. The nisprefadm -F command must always be run by itself on the machine you want it to apply to. You cannot use the -G option to update the cache managers of all machines in a domain. The nisprefadm -F command must be run on each machine individually.