Having a little difficulty interpreting your question.
The following would allow you to control which hosts are allowed to interact with NTP services on the Cisco device, and whether they can interact as clients or peers.
access-list 2 remark --- NTP Peers.
access-list 2 permit
access-list 2 deny any log
access-list 3 remark --- NTP Clients.
access-list 3 permit 192.168.1.0 0.0.0.255
access-list 3 deny any
ntp source Loopback0
ntp access-group peer 2
ntp access-group serve-only 3
ntp server
Perhaps refer to:
Network Time Protocol: Best Practices White Paper
http://www.cisco.com/warp/public/126/ntpm.pdf
