1920 switches NTP

[Dunky]

I am new to these switches, having previoulsy used Cisco and ProCurves.

I have three issues that are really causing me stress at present as I just cannot get them to work.  Rather than posting all three issues I will keep each post to a single issue.

There are seven 1920-24D-PoE+ switches in the configuration.

NTP

I simply cannot get it to work.

I have tried pointing the switches to the firewall and I can see the packets being allowed on the firewall but the clock status on the switches still says unsynchronized.

The only fields I have filled in on the NTP tab is External Reference Source NTP Server 1 which is set to the firewalls LAN IP address, and the timezone.

I cant see that I am missing anything on what should be so simple and just work!

Thanks
Steve

[AlexisKoch]

Hello,

your firewall is your NTP server? Is there some kind of security configured on it (like a key)?

Can you put a sniffer between the switch and the firewall and look if the firewall is answering the request? And don't know if it's the case of the switches, but sometimes machines don't sync if there is a big time difference...

Regards,

Alexis

[Dunky]

I never thought of the time difference - the switches were showing a time in 2000 !!

Changed to within 2 minutes of the firewall and they are still not synchonizing.

Yes the firewall is acting as my NTP server.

I can see the packets arriving on the firewall as I set it to log them.  I will have to have a look with Wireshark next week and see exactly what traffic is coming back from the firewall, although I have a firewall acting as an NTP server at other sites without any problems, albeit this is a different model (much higher spec).

[-TM-]

I've setup NTP on a 1920-24 (JG924a) without any issues. to 2 internal NTP Servers on SOHO Cable Router.

1.) Try to clear all key and secret fields again to avoid any NTP authorization

2.) Check if NTP Server on your Firewall allows unauthorized NPT clients

3.) Check Routing. Does your firewall know about a route back to the connected Interface?

4.) Ist there a firewall rule dropping the packets?

5.) try another NTP Server

[Dunky]

Thanks, good to know that you have it working, so I should be able to resolve it.

What version are you running if I may ask?

[Dunky · Accepted solution]

Solved - It was the firewall.

On a WatchGuard via the WebUI, go to System> NTP and there is a tick box to enable as NTP server !!

[-TM-]

520-r1107

520-r1110

520-r1111