NIS can be secure but not on your network.
irbs 864# rpcinfo -p dobie.ebs.net
program vers proto port
100000 2 tcp 111 portmapper
100000 2 udp 111 portmapper
100005 1 udp 675 mountd
100005 1 tcp 677 mountd
100003 2 udp 2049 nfs
100003 2 tcp 2049 nfs
150001 1 udp 680 pcnfsd
150001 2 udp 680 pcnfsd
150001 1 tcp 683 pcnfsd
150001 2 tcp 683 pcnfsd
What rpcinfo has revealed is an exercise for the reader.
John Capo jc@irbs.com
IRBS Engineering FreeBSD Servers and Workstations
(954) 792-9551 Unix/Internet Consulting - ISP Solutions