3CX V20 – FQDN Resolves to Incorrect Public IP, Web Client Unreachable

Volfcommunications

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Hello 3CX Community,

We are experiencing a DNS issue with our self-managed 3CX V20 Update 9 (Build 995), Basic Edition installation.

FQDN: vlfcom.sd.3cx.us

Correct server public IP: 40.160.231.40

Current authoritative DNS A record: 90.152.3.181

We have confirmed the following:

  • The server's network interface and outbound public IP are both 40.160.231.40.
  • HTTPS responds with HTTP 200 OK when connecting directly to 40.160.231.40 using the correct hostname.
  • Google DNS (8.8.8.8), Cloudflare DNS (1.1.1.1), and the authoritative Cloudflare nameserver all return 90.152.3.181.
  • All 3CX services are running.
  • Refreshing the 3CX licence did not correct the DNS record.
As a result, our employees cannot access the Web Client or use their welcome-email activation links.

Since this is a 3CX-managed FQDN, is there a supported way to trigger a DNS update, or could a 3CX representative investigate the incorrect A record?

We would appreciate assistance resolving this without interrupting our production PBX.

Thank you.
 
Hi @Volfcommunications please edit your post to remove sensitive information, such as your FQDN and public IP addresses.

Regarding this issue I can notice that the subscription is installed in two different servers. To resolve this:
  • Ensure only one machine remains active; the secondary or test server must be turned off or deleted.
  • Update network settings on the active machine:
    • Navigate to Advanced > Network, select Dynamic IP, and apply the changes.
    • Go to Dashboard > Services and restart the 3CXDatabaseServer. This forces the system to detect your current public IP and update your FQDN.
  • Once the service has restarted, go to System > License and click Refresh License Key.
  • Flush your local DNS cache. Note that full DNS propagation may take a short time before the FQDN resolves to the correct public IP.
Have a good day!
 
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