3CX Activation Error

[isscasd]

We are a recent customer with version 18.0.3.461. During installation everything goes fine and our information for the FQDN, etc. is passed to our customer portal. Unfortunately, once the software installs we receive an activation error and says our primary dns can not resolve.

We have confirmed that our DNS and PBX server can resolve activate.3cx.com and ping it with no problem. We have also done 3CX firewall checks with no issues. In order to get the activation to perform successfully we need to change the DNS on the NIC to 8.8.8.8 and it goes through instantly. We can't do this long term as we need AD login to the server so we need our internal DNS configured.

Based on other forms posted here, this issue appears to have started with the v18 introduction of activate.3cx.com instead of activation.3cx.com. It's worth mentioning that 2 years ago we used a smaller deployment of 3cx with no issues before this change. In doing DNS lookups for activate.3cx.com it appears that 3CX has moved to cloudflare for their DNS provider. Is it possible that they have DNSSEC enabled and it is not trusting our internal dns queries, etc?

 

[Charles_3CX]

Regarding your issue and specifically DNS requirements, when on a domain, you will need to make sure that you have forwarders configured to 8.8.8.8. The DNS requirements for the activation have always been this way and require a clear and precise answer from DNS in order to activate. You can check this by starting a Wireshark capture on the machine or through the management console (providing Wireshark is installed ont the PBX machine) opening a new tab into the Activity log > choosing all interfaces and pressing capture, then back to the other tab into the management console and under the Settings > licensing section pressing refresh license ley information. Tip: Before doing this, under CMD issue the command ipconfig /flushdns. Then once the error appears in the license section, stop the capture and download the dump.pcap, open it, and enter DNS in the search area check the DNS query for activate.3cx.com and see if there is an A record response for the query.

 

[isscasd]

Charles, we have 8.8.8.8 set as the forwarder and receive an A record response as can be seen in the screenshot, but the activation still fails. The initial activation goes fine during install, but the repeated checks fail. Our team also noticed that the TTL on the DNS record is set to 0. Could it be timing out before the response is received and the TTL for activate.3cx.com needs to be increased?

 

[SweetAction]

Another thread with same discussion: https://www.3cx.com/community/threads/license-activation-issue.115295/

I suspect same PBX based on the IPs on wireshark.