RasPi, RTC and NTP (Not working)

I seem to be going in circles.

As it is now, I have a RasPi 3B+ and a RTC module.
The RTC survives a power down and reboot and the RasPi gets its time from the RTC - I hope.
But the time on the Pi is correct on power up.

Being a sucker for doing the impossible I want to use that machine as my network’s NTP server.

I’ve supposedly got it working, but I can’t get any of my devices to see it and get their time from it.

Port 123 is for the NTP, and when I scan that RasPi from another machine the port isn’t open.

I’ve been down a few rabbit holes and not got anywhere.

Has anyone here done what I am trying to do and got it working?

Thanks in advance.

Hi James,

It is on a RasPi and as far as I know there is no firewall.

(Good news though)
And that is…

As with so many of my problems: If I don’t ask they stay.
As soon as I ask: most of them go away.

I was stuck proving the NTP server was working.
I don’t know enough to do it from a terminal/CLI.

Shortly after posting the question I found a “program” I could use and it gave me the right time.

Also, I think I was looking too quickly after powering on another device which wasn’t getting the NTP. (A tasmota flashed device)
And annoyingly - of course - I have two. One was working and one wasn’t.
Now they both are with the right time.

Sorry for posting the question as it now seems to be ok.

Here is some more information though. As I am not 100% sure all is good with things.

From the RasPI

pi@TimePi:~ $ sudo nmap -sU
Starting Nmap 7.70 ( https://nmap.org ) at 2022-06-14 07:44 AEST
Nmap scan report for TimePi (
Host is up (0.00019s latency).
Not shown: 992 closed ports
53/udp   open|filtered domain
67/udp   open|filtered dhcps
68/udp   open|filtered dhcpc
111/udp  open          rpcbind
123/udp  open          ntp
631/udp  open|filtered ipp
2049/udp open          nfs
5353/udp open|filtered zeroconf

Nmap done: 1 IP address (1 host up) scanned in 27.99 seconds
pi@TimePi:~ $ 

It is ok. Port 123 is open.

From another machine:

me@me-desktop:~$ netstat -a|grep :ntp

No NTP listed.

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