sudo  lsof -i:123

COMMAND PID USER   FD   TYPE DEVICE SIZE/OFF NODE NAME
ntpd    442  ntp   16u  IPv6  14172      0t0  UDP *:ntp 
ntpd    442  ntp   17u  IPv4  14175      0t0  UDP *:ntp 
ntpd    442  ntp   18u  IPv4  14179      0t0  UDP localhost:ntp 
ntpd    442  ntp   19u  IPv4  14181      0t0  UDP ip-72-167-36-226.ip.secureserver.net:ntp 
ntpd    442  ntp   20u  IPv6  14183      0t0  UDP ip6-localhost:ntp 
ntpd    442  ntp   24u  IPv4  16851      0t0  UDP 10.8.0.1:ntp 
ntpd    442  ntp   25u  IPv6  16854      0t0  UDP [fe80::c637:72ff:fe15:7a16]:ntp 
ntpd    442  ntp   26u  IPv6  16856      0t0  UDP [fe80::f1e3:9b59:22d5:f40d]:ntp 

 sudo kill -9 pid 442 #修改PID

 sudo ntpdate time.apple.com