Final answer:
Cluster ActiveGates connect to the Dynatrace Server using Port 443, which is the standard port for secure HTTPS traffic ensuring encrypted and secure communications.
Step-by-step explanation:
Environment and Cluster ActiveGates make outgoing connections to the Dynatrace Server on Port 443. This port is widely used for secure network communications, where encrypted data is sent over a network, ensuring the security of the data transmitted. Cluster ActiveGates are components in the Dynatrace monitoring infrastructure that, among other tasks, ensure secure communication between monitored environments and the Dynatrace Server.