System Administration Guide: Naming and Directory Services (NIS+)

Replacing an Entire Preferred Server List in NIS+

To replace an entire list of preferred servers for a subnet or machine in either a global client_info table or a machine in its local client_info file, run nisprefadm with the -u option.

The -u option operates the same way as the -a option, except that -u first deletes any existing server preferences for the machine or subnet before adding the new ones that you specify. (If there are existing preferences, the -a option adds the new ones to the old list.)

See How to Set Global Preferences for an Individual NIS+ Machine for an example using the -u option.