Troubleshooting "Connection to the Cloud Server Could Not Be Established" Error on Bitdefender Agent (On-Premises)

Troubleshooting "Connection to the Cloud Server Could Not Be Established" Error on Bitdefender Agent (On-Premises)

Reported Concern: Error indicating "Connection to the cloud server could not be established" on the Bitdefender agent.

Observation: When the Bitdefender agent fails to connect to the cloud server, consider the following checks:

1. Network Firewall Configuration: Ensure that the Bitdefender communication ports are allowed through the network firewall. The following ports must be open for proper communication: 80; 443 and 8443

2. Proxy misconfigured: If a proxy is in use, verify that it is configured correctly. A misconfigured proxy can prevent the agent from connecting to the cloud server.

3. Check if the thawte_Primary_Root_CA certificate is missing from the affected machine.

Resolution: 

- Verify the communication of the required ports from the affected machine using the telnet command.
For example: telnet <machine_IP> <port_number>

If the ports do not respond to the telnet command, share the following link to help open the required ports on the firewall:

- Ensure that the Bitdefender agent can connect to the Bitdefender cloud services via the following domain:
 nimbus.bitdefender.net. 
For example: telnet <url> <port_number>

- The issue may also occur if one of the below URL's are being getting blocked:
 mclb-gcp.nimbus.bitdefender.net
 eu.nimbus.bitdefender.net
 us.nimbus.bitdefender.net
 elb-fra-gcp.nimbus.bitdefender.net
 elb-lon-gcp.nimbus.bitdefender.net
 elb-nvi-gcp.nimbus.bitdefender.net
 elb-ore-gcp.nimbus.bitdefender.net
 elb-iow-gcp.nimbus.bitdefender.net
 elb-tky-gcp.nimbus.bitdefender.net

Ensure these URLs are not being blocked or filtered by your firewall or proxy 

- If a proxy server is used, verify the proxy settings. Incorrect proxy configuration could prevent the agent from reaching the cloud server.

- If the thawte_Primary_Root_CA certificate is missing, download and install it as a Trusted Root Certificate on the affected machine. You can obtain the certificate from the following link: https://www.digicert.com/kb/digicert-root-certificates.htm


After performing the above troubleshooting steps, if the issue still remains unresolved, proceed with the gathering support tool logs and error screenshots to escalate it with OEM team for further analysis.