The SERVICE ports of the M580 system are NOT intended to be connected together through the CONTROL network. Do NOT connect, directly, or through a switch, two or more SERVICE ports from different M580 systems. This applies on all service ports: CPU, CRA and DRS.
The reason for this is that the SERVICE ports are in the same subnet as the DEVICE network. At startup, and during some configuration sequences, some broadcast messaging could flood parts of the system. A message broadcast from any CRA is forwarded on the service port, and would go further if it was connected on another M580.