Comtech EF Data CDM-625 - Manual (Page 380)

CDM-625 Advanced Satellite Modem Revision 15
Ethernet Network Configuration MN-CDM625
16–2
16.2.2 Modes of Ethernet Operation
The Ethernet interface is configurable for Managed Switch Mode when the optional IP Packet
Processor is either not installed or installed but disabled; or in Router Mode or Managed
Switch Mode when the optional IP Packet Processor is installed and enabled .
This interface design allows for multiple customer Ethernet interfaces, as well as the
convenience of daisy-chaining together of multiple CDM-625s.
Additionally, because the M&C processor is connected to the internal Ethernet Switch, M&C
traffic is available via all LAN interfaces as well as via the over-the-air WAN interface.
16.2.3 Ethernet Networking Loops
It should be noted that care must be taken to avoid Ethernet Networking Loops. Specifically,
the network operator must make sure to avoid connecting multiple ports of the CDM-625 to the
same external Ethernet switch, as shown in Figure 16-2.
Figure 16-3 shows a simplified version of this loop. As shown here, two switches have been
connected – each switch has two or more separate connections. This is not how the CDM-625’s
Ethernet switches are designed to be used, and this configuration will cause a network outage.
Figure 16-2. Improper Use of External Ethernet Switch with CDM-625
Figure 16-3. Ethernet Networking Loop Example (Simplified)