Troubleshooting Tip: NTP synchronization

[cmaheu]

Description

This article describes how to troubleshoot synchronization issues between FortiNAC and the NTP server.

Scope

FortiNAC.

Solution

The NTP Server is defined in the Administration UI under System -> Settings -> System Management -> NTP and Time Zone. 

Status is confirmed by using the ntpstat command in the CLI. 

Example:

> ntpstat
unsynchronised
polling server every 8 s

1. Verify that the NTP server specified in the Administration UI under System -> Settings -> System Management -> NTP and Time Zone can be reached. Run the following command in the CLI: 

ntpq -p

The NTP server cannot be reached if the 'when' column is blank or the 'st' column is 16.

Failed example:

> ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 149.20.176.27   .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 time.nullrouten .INIT.          16 u    - 1024    0    0.000    0.000   0.000

2. If the server cannot be reached, either troubleshoot why the server cannot be reached or try changing the NTP server in the Administration UI to a known good server. If the NTP server is defined as a name, compare the resulting IP address listed in results for 'ntpq -p'.  If different than a known good NTP server synchronization, try using the known good IP address.
   

3. Once the NTP Server has been changed in the UI and the system has been restarted, verify the server is now reachable.

Working example:

> ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 162.159.200.1   10.16.12.8       3 u   33   64    7   16.481    5.305   4.260


> ntpstat
synchronised to NTP server (162.159.200.1) at stratum 4
   time correct to within 970 ms
   polling server every 64 s

Note: ntpstat results may not show the system synchronized immediately. It may take several minutes. 

If the system time is dramatically different than the NTP server, then simply synchronizing may not be enough to correct the time automatically. For instructions on correcting the clock, see the related KB article below.

For more information on NTP troubleshooting, refer to Linux's time synchronization with NTP troubleshooting guide.

Related article:

Technical Tip: Adjusting NTP for drift