Error: "This site can't be reached" ERR_CONNECTION_TIMED_OUT when accessing HCX Cloud Manager

Products

• VMware Cloud on AWS

Issue/Introduction

When attempting to access the HCX Cloud Manager interface from a Windows machine, the following error appears in the web browser:

Error: "This site can't be reached" ERR_CONNECTION_TIMED_OUT

The browser displays suggestions to check the connection, proxy, and firewall settings, or run Windows Network Diagnostics.

The HCX Manager FQDN or IP address cannot be reached or pinged from on-premises systems. However, vCenter Server remains accessible from the same location.

Within vCenter Server, site pairing shows as down despite existing network profile and compute manager configurations being present.

Steps to validate the issue:

1. Log in to the cloud vCenter Server with administrative credentials
2. Verify that the HCX Manager is pingable from vCenter Server on the same subnet
3. If the HCX Manager is pingable locally within the SDDC but not accessible externally, proceed with the following steps
4. Navigate to port 9443 on the HCX Manager within vCenter
5. Check the connection status of vCenter Server and NSX to HCX Manager - both show as disconnected
6. Verify that HCX site pairing status shows as down
7. Confirm that existing network profiles and compute manager configurations are still present

If the HCX Manager is pingable from vCenter on the same subnet but the connections on port 9443 are disconnected, this indicates the issue described in this article.

Environment

VMware HCX
VMware vCenter Server
VMware NSX

Cause

The vCenter Server and NSX are not properly connected to the HCX Manager on port 9443 within the SDDC environment.

The HCX Cloud Manager requires active connections from both vCenter Server and NSX on port 9443 for proper operation. When these management plane connections are lost or disconnected, the HCX Manager service fails to function correctly, causing the platform to become unreachable from external networks.

Although the HCX Manager VM remains running and is accessible locally within the SDDC, the disconnected management connections prevent proper service operation, resulting in connection timeouts when accessed from on-premises systems.

Resolution

To restore connectivity to the HCX Cloud platform, re-establish the management connections and restart the HCX service. These steps resolve the internal disconnection issue, which in turn restores external network accessibility:

1. Log in to vCenter Server with administrative credentials
2. Navigate to the HCX Manager configuration
3. Access port 9443 on the HCX Manager
4. Verify that vCenter Server connection shows as disconnected
5. Re-establish the vCenter Server connection to HCX Manager on port 9443
6. Verify that NSX connection shows as disconnected
7. Re-establish the NSX connection to HCX Manager on port 9443
8. Reboot the HCX Manager VM to apply the configuration changes
9. Wait for the HCX Manager to fully restart (approximately 5-10 minutes)
10. Test connectivity by pinging the HCX Manager FQDN or IP address from the on-premises Windows machine
11. Verify that the HCX Cloud Manager interface is now accessible from the web browser
12. Confirm that site pairing status shows as connected in vCenter Server
13. Verify that the "ERR_CONNECTION_TIMED_OUT" error no longer appears

After the HCX Manager VM restarts with restored management connections, the platform becomes accessible from external networks and site pairing is restored.