ArcGIS Monitor uses specific ports to communicate with other machines. The ports you need to allow on your firewall are described below.
HTTPS port 30443
ArcGIS Monitor Server only communicates through port 30443 by default. Ensure that your firewall allows communication through this port. Your users and ArcGIS Monitor Agent access Monitor Server through this port.
HTTP port 30080
Monitor Server supports HTTPS communication by default, and communication through port 30080 is not allowed. Administrators can change this setting in Monitor Server to allow HTTP plaintext communication through port 30080, but this is a less secure option.
Internally used ports
Ports 30001 through 30010 are used internally by Monitor Server. You do not need to open these ports for access by other machines; however, you should be aware that Monitor Server is using them in case you run other applications that require the same ports.
Firewalls between Monitor machines
Firewalls may exist between Monitor machines that are located in different network environments. Monitor Agent and Monitor Server only communicate over port 30443 or port 30080 when HTTP plaintext communication is allowed. The port used for communication is specified during the Monitor Agent registration process. Depending on your firewall settings, you may need to adjust inbound rules for Monitor Server and outbound rules for Monitor Agent.