Reference Guide – DOC. 7150B
3-Series Control Systems
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35
Control Subnet Architecture
Even if nothing is plugged into the CONTROL SUBNET
port on the back on the
control system, there are still some devices present on the Control Subnet:
•
Control System CPU (Where AV programs run)
•
Optional Expansion cards (PRO and AV3 only)
This design is in place to ensure that the Crestron CPU and optional expansion
cards are protected from malicious packets on the LAN. Refer to the diagram
below for more information on how these components work together.
Public LAN/Control Subnet Diagram
The firewall rules permit entry to only the traffic that is listened to by the CPU.
As a result, a port scan will only show ports that are listened to by the CPU. Users
can set up manual port forwarding rules to make custom connections to the
devices on the Control Subnet. For more information, refer to “Appendix B: Port
Forwarding” on page 63.
Crestron Toolbox can create custom port forwarding rules in the 64000-64299
range to enable management of the devices on the Control Subnet. These port
forwarding rules are created when the tool connects and are broken down when
the tool disconnects or when the device is rebooted.
