A customer engineer is unable to securely connect to vCenter using their laptop.

When securely connecting to vCenter, the customer engineer needs to provide the correct source and destination port numbers. The valid source port range for secure connections is typically from 49152 to 65535, which are ephemeral ports assigned by the operating system for outbound connections. The destination port for secure connections to vCenter is 443, which is the standard port for HTTPS.

References:

VMware vCenter documentation.

Networking standards for secure HTTPS connections.