Install and configure NTP on FreeBSD 11
In this article will be described what use NTP to synchronize system time on FreeBSD. I use FreeBSD 11 that ran as VPS in Hetzner cloud.
Previously you should check what version is installed on your machine. Use for this command ntpd --version. Result:
ntpd 4.2.8p10-a (1)
If you have NTP server that version is less 4.2.7 you should update it because you might be attacked.
Using a portsnap to update your local ports:
portsnap fetch extract
portsnap fetch update
After that instal zoneinfo package and copy selected local zone to change your timezone (my zone is Europe/Moscow:
cd /usr/ports/misc/zoneinfo && make install clean
cp /usr/share/zoneinfo/Europe/Moscow /etc/localtime
Editing your NTP configuration file /etc/ntp.conf:
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1
restrict -6 ::1
server ntp1.hetzner.de iburst
server ntp2.hetzner.de iburst
server ntp3.hetzner.de iburst
Don’t forget setup your servers in these parameters:
server ntp#.hetzner.de iburst– use this server to synchronize time;iburstkeyword allows to speed up first connection
And now only need to add a command that will allow running NTP on startup (rc.conf):
echo ntpd_enable=\"YES\" >> /etc/rc.conf
echo ntpd_sync_on_start=\"YES\" >> /etc/rc.conf
Parameter ntpd_sync_on_start is setting YES to syncs the system’s clock on startup and to remove a restriction a lot time offset.
Finally lets start a local NTP server:
/etc/rc.d/ntpd start
Some moments ago your local system time will update and you can check a status on this:
# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
+ntp1.hetzner.de 192.53.103.108 2 u 1 64 1 2.864 -0.889 0.153
+ntp2.hetzner.de 192.53.103.108 2 u 4 64 1 0.328 0.219 0.114
*ntp3.hetzner.de 192.53.103.108 2 u 2 64 1 0.306 0.832 0.092
# ntpdate -q localhost
server 127.0.0.1, stratum 3, offset -0.000008, delay 0.02568
server ::1, stratum 3, offset 0.000005, delay 0.02571
ntpdate[52224]: adjust time server 127.0.0.1 offset -0.000008 sec
If you want to sync onetime use this command:
# ntpdate -v -b ntp1.hetzner.de
ntpdate[11356]: ntpdate 4.2.8p10-a (1)
ntpdate[11356]: step time server 213.239.239.164 offset 0.004194 sec
Additional information:
This links might useful to get any additional information: