nas:~# cat /etc/ypserv.securenets 
#
# securenets    This file defines the access rights to your NIS server
#               for NIS clients (and slave servers - ypxfrd uses this
#               file too). This file contains netmask/network pairs.
#               A clients IP address needs to match with at least one
#               of those.
#
#               One can use the word "host" instead of a netmask of
#               255.255.255.255. Only IP addresses are allowed in this
#               file, not hostnames.
#
# Always allow access for localhost
255.0.0.0       127.0.0.0

# This line gives access to everybody. PLEASE ADJUST!
255.255.255.0           192.168.1.0

######################################

nas:~# rpcinfo -p localhost
   program vers proto   port
    100000    2   tcp    111  portmapper
    100000    2   udp    111  portmapper
    100024    1   udp  32768  status
    100024    1   tcp  41154  status
    100004    2   udp    663  ypserv
    100004    1   udp    663  ypserv
    100004    2   tcp    664  ypserv
    100004    1   tcp    664  ypserv
    100009    1   udp    666  yppasswdd
 600100069    1   udp    669  fypxfrd
 600100069    1   tcp    670  fypxfrd
    100007    2   udp    678  ypbind
    100007    1   udp    678  ypbind
    100007    2   tcp    679  ypbind
    100007    1   tcp    679  ypbind

######################################

nas:~# rpcinfo -p nas
No remote programs registered.