NTP client not syncing with server

[godatum2]

I have a Ubuntu server running NTP. This seems to be working OK

sudo ntpq -npcrv
     remote           refid      st t when poll reach   delay   offset 
jitter
==============================================================================
*216.239.35.0    .GOOG.           1 u  302 1024  377   16.475    0.523  
0.256
+216.239.35.4    .GOOG.           1 u  793 1024  377   20.461    1.155  
1.203
+216.239.35.8    .GOOG.           1 u  140 1024  377   21.860    1.204  
0.587
-216.239.35.12   .GOOG.           1 u  971 1024  377   19.215   -0.035  
2.464
associd=0 status=0615 leap_none, sync_ntp, 1 event, clock_sync, leap=00, stratum=2,
precision=-23, rootdelay=16.475, rootdisp=29.552, refid=216.239.35.0,
reftime=e96b46fd.e6fd1f35  Mon, Feb  5 2024 11:37:33.902,
clock=e96b482c.941f5352  Mon, Feb  5 2024 11:42:36.578, peer=33036,
tc=10, mintc=3, offset=0.834, frequency=22.740, sys_jitter=0.522,
clk_jitter=0.358, clk_wander=0.047

On my Ubuntu client the time is not syncing as shown my the leap_alarm state. The time was about 10 mins out, so I manually adjusted it and restarted the ntp service. But it's still showing as leap_alarm.

ntpq -npcrv
     remote           refid      st t when poll reach   delay   offset 
jitter
==============================================================================
 srv1.company.loc .POOL.          16 p    -   64    0    0.000    0.000  
0.000
associd=0 status=c016 leap_alarm, sync_unspec, 1 event, restart, leap=11,
stratum=16, precision=-24, rootdelay=0.000, rootdisp=3.795, refid=INIT,
reftime=00000000.00000000  Thu, Feb  7 2036  6:28:16.000,
clock=e96b4843.14967997  Mon, Feb  5 2024 11:42:59.080, peer=0, tc=3,
mintc=3, offset=0.000000, frequency=4.418, sys_jitter=0.000000,
clk_jitter=0.000, clk_wander=0.000

 sudo ntpdate -q srv1.company.local
server 10.1.0.1, stratum 2, offset -0.193649, delay 0.04465
 5 Feb 11:45:17 ntpdate[12231]: adjust time server IP offset
-0.193649 sec

Running:

sudo service ntp stop
sudo ntpdate srv1.company.local
        5 Feb 12:05:14 ntpdate[13086]: adjust time server IP offset -0.193957 sec
sudo service ntp start

[MAFoElffen]

You missed providing some information that would help with this...

Do you have firewall rules to allow the NTP updates through from NTP client to NTP server?

sudo ufw allow from any to any port 123 proto udp

In the hosts file of the clients, did you specify the IP and hostname of the NTP server in their hosts file? Or do you have verified local DNS resolv?

Did you disable the systemd timesyncd service on the NTP client so that it doesn't fight and conflict with NTP client?

Did you configure the /etc/ntp.conf file to add your NTP server as the new time server by adding a line

server <NTP-server-name> prefer iburst

Substituting the name with what the NTP host is?

Did you restart the NTP services on the clients and host to pick up any changes?

[TheFu]

Isn't NTP deprecated for security issues? Not that it is any better, but I switched to Chrony a few years ago. Don't forget to disable/purse systemd-timed.

https://www.ntpsec.org/ has some specific hardware sync clocks available too. Most tie into GPS hardware, since GPS provided very accurate time anywhere on Earth.

[godatum2]

The firewall is allowing UDP 123.

I can resolve DNS for srv1.company.local using nslookup.

Output of timedatectl:

      
Local time: Tue 2024-02-06 10:55:42 GMT
Universal time: Tue 2024-02-06 10:55:42 UTC
RTC time: Tue 2024-02-06 10:55:42
Time zone: Europe/London (GMT, +0000)
 Network time on: yes
NTP synchronized: no
 RTC in local TZ: no

Contents of /etc/ntp.conf:

driftfile /var/lib/ntp/ntp.drift

pool srv1.company.local

# by default act only as a basic NTP client
restrict -4 default nomodify nopeer noquery notrap
restrict -6 default nomodify nopeer noquery notrap

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

I did restart the NTP service on the srv1.company.local host and client.

On the host running sudo ss -lu:

State               Recv-Q              Send-Q                           Local Address:Port                             Peer Address:Port             Process

UNCONN              0                   0                                   IP:NTP                                               *:*

On the client:

sudo nmap -sU srv1.company.local

PORT       STATE    SERVICE
123/udp  open     ntp

[SeijiSensei]

Have you run ntpdate with the -v switch enabled?

[godatum2]

Have you run ntpdate with the -v switch enabled?

I get an error:

no servers can be used, exiting