How To Change NTP Configuration

Warning

Any action on the Command-Line Interface (CLI) using the root, osadmin, or autoboss account may cause irreversible, detrimental changes to the product. Actions taken without direct communication with the IP Fabric Support or Solution Architect teams can render the system unusable.

Since version 7.x, the IP Fabric appliance uses ntpsec for time synchronization. To change the NTP configuration, edit the /etc/ntpsec/ntp.conf file and restart the service.

Steps

Edit the NTP configuration file:
```
sudo vi /etc/ntpsec/ntp.conf
```
Restart the NTP service to apply changes:
```
sudo systemctl restart ntpsec.service
```
Check that the service is running:
```
sudo systemctl status ntpsec.service
```
The output should show active (running):

Default Configuration

The default /etc/ntpsec/ntp.conf file uses the Debian NTP pool:

/etc/ntpsec/ntp.conf

# /etc/ntpsec/ntp.conf, configuration for ntpd; see ntp.conf(5) for help

driftfile /var/lib/ntpsec/ntp.drift
leapfile /usr/share/zoneinfo/leap-seconds.list

# This should be maxclock 7, but the pool entries count towards maxclock.
tos maxclock 11

# pool.ntp.org maps to about 1000 low-stratum NTP servers.  Your server will
# pick a different set every time it starts up.  Please consider joining the
# pool: <https://www.pool.ntp.org/join.html>
pool 0.debian.pool.ntp.org iburst
pool 1.debian.pool.ntp.org iburst
pool 2.debian.pool.ntp.org iburst

tos minclock 4 minsane 3

# Access control configuration
restrict default kod nomodify noquery limited

# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1

Example: Adding a Custom NTP Server

To add your own NTP server (e.g., an internal time source at 10.0.1.100), add a server line to the configuration:

/etc/ntpsec/ntp.conf

# /etc/ntpsec/ntp.conf, configuration for ntpd; see ntp.conf(5) for help

driftfile /var/lib/ntpsec/ntp.drift
leapfile /usr/share/zoneinfo/leap-seconds.list

# This should be maxclock 7, but the pool entries count towards maxclock.
tos maxclock 11

# Custom NTP server (added)
server 10.0.1.100 iburst prefer

# pool.ntp.org maps to about 1000 low-stratum NTP servers.  Your server will
# pick a different set every time it starts up.  Please consider joining the
# pool: <https://www.pool.ntp.org/join.html>
pool 0.debian.pool.ntp.org iburst
pool 1.debian.pool.ntp.org iburst
pool 2.debian.pool.ntp.org iburst

tos minclock 4 minsane 3

# Access control configuration
restrict default kod nomodify noquery limited

# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1

Note

Use server for a specific NTP server and pool for a pool of servers.
The iburst option speeds up initial synchronization.
The prefer option marks the server as the preferred time source.

After saving the file, restart the service:

sudo systemctl restart ntpsec.service

To check synchronization with the new server:

ntpq -pn

The output shows all configured NTP sources with their status. The * symbol marks the currently selected source:

     remote           refid      st t when poll reach   delay   offset   jitter
==============================================================================
*10.0.1.100      .GPS.            1 u   64  128  377    0.523   -0.012    0.015
+0.debian.pool.n .PPS.            1 u  120  256  377   12.345    1.234    0.567
+1.debian.pool.n .PPS.            2 u   95  256  377   15.678    0.890    0.432
+2.debian.pool.n .ATOM.           2 u  200  256  377   20.123   -2.345    0.789