Stun stopped working yesterday at 05:30 CET?

[nobody]

Since yesterday about 5:30CET a 3CX system which is set to dynamic IP refuses to register the trunks because "no transport found". If I deactivate Stun and set to static IP everything works fine. However there was no change, and it did work ok with Stun since the last update.
It is the only "free" instance I manage. All other pbx with paid licenses run fine, parts of them also use Stun.
I waited 24hrs, enabled Stun again. No change.
Any clue where to start searching?

TIA

 

[StefanW]

which stun server do you querry from the host (in order as they are set)?

 

[nobody]

The 3cx servers:
stun-eu.3cx.com
stun3.3cx.com
stun3.3cx.com

1200seconds query interval

 

[nobody]

I tried a few more things:
Checked if software is up to date: yes
rerun the firewall checker - ok
changed all stun servers to known public stun servers - no change
lowered the stun query interval to 600, changed everything back to the 3cx stun servers, made a restart:
Still none of the trunks register, but after 10 minutes they did this time (I could not watch with wireshark at the point when the system starts because I have wireshark running only on the machine hosting the pbx, but at the next try I saw the request and response -was there immediately).
Makes no sense to me. Yesterday morning the pbx was offline for several hours using the same settings.
For the last 8 weeks it worked fine - there were even two power outages.

When does the pbx tries the first request to the stun server? Does it check if internet connectivity is present before it make the first try? The PC is a modern I5-4590T, 8GB Ram, 128GB SSD, exclusively using its resources for the PBX. only 5 phones ,Windows 10 Pro 1803, boots in about 30seconds.
In the log there is a warning about a problem resolving stun3.3cx.com after the start. but the first stun server is stun-eu.3cx.com.
Maybe the 3cx services start to early?

I try to set all services to delayed exept the database server.
Now it registers instantly after the 2min delayed start.

 

[nobody]

This topic might be tagged as solved (however the questions why the 3cx system does not wait until the network is fully operational remains).

 

[YiannisH_3CX]

This topic might be tagged as solved (however the questions why the 3cx system does not wait until the network is fully operational remains).

Glad to see you were able to work around the issue and thank you for updating the thread with your solution. Unfortunately we were not able to replicate this in a test environment so it is hard to say what the issue is but it could be the case that the SIP server service started before your NIC got an IP so it got bound to the wrong IP. if that is the case then a restart of the SIP server service should be enough to fix the issue. The PBX will send a STUN request before every call but if the IP it is bound on is wrong that it will not get a valid reply and will cause the issue you are describing.