OS: RHEL6
Protpcol: UDP
Default port: 123
NTP installed by default.
System A (server), IP 10.10.10.1
Edit /etc/ntp.conf:
# Hosts on local network are less restricted.
restrict 10.10.10.0 mask 255.255.255.0 nomodify notrap
. . .
# Undisciplined Local Clock. This is a fake driver intended for backup
# and when no outside source of synchronized time is available.
server 127.127.1.0 # local clock
fudge 127.127.1.0 stratum 10
Autostart and run:
chkconfig ntpd on
service ntpd start
System B (client), IP 10.10.10.4
Add to /etc/ntp.conf:
server 10.10.10.1
Check time on server:
ntpdate 10.10.10.1
Update time from server:
ntpdate -u 10.10.10.1
Autostart and run:
chkconfig ntpd on
service ntpd start
Verify:
# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
10.10.10.1 LOCAL(0) 11 u 57 64 3 1.900 3598849 7.946
[/bahs]
Notes:
1. ntpdate - work if service ntpd is down.
2. After restart of NTP service. You can see error:
ntpdate 10.10.10.1
21 Mar 22:22:34 ntpdate[2421]: no server suitable for synchronization found
After 1 minute it should be ok.