Become superuser.
Properly configure the hosts line in the /etc/nsswitch.conf file to read: hosts: nisplus dns files.
In this implementation of NIS, if a /etc/resolv.conf file exists on the server, ypstart automatically starts the ypserv daemon with the -d option to forward requests to DNS. To stop forwarding to DNS, edit the /usr/lib/netsvc/yp/ypstart script to remove the -d option from the ypserv command. You must then reboot the machine.