Comtech EF Data CRS-180 - Manual (Page 27)

CRS-180 70/140 MHz IF 1:1 Redundancy Switch MN/CRS180.IOM
Introduction Revision 11
1–7
Figure 1-5. CDM-625/A, -760, -750, -710G, -710, -700 1:1 IP Redundancy Managed
Switch Mode – Switchover
As shown in Figure 1-5, in the event of a fault occurring on the Online Modem ‘A’, the following
will occur:
• Modem ‘A’ goes Offline and disables its Ethernet data interface.
• Simultaneously, Modem ‘B’ goes Online and enables its Ethernet data interface.
• Layer 2 switch ‘A’ senses that Port 4 is no longer active and clears the CAM table entries for
that port.
• When the next Ethernet packet from Local PC ‘A’ destined for Remote PC ‘B’ arrives at
Switch ‘A’, there is no CAM entry for the PC ‘B’ MAC, so it will be broadcast to all active
ports.
• When the next Ethernet packet from Remote PC ‘B’ arrives at Switch ‘A’, Switch ‘A’
dynamically adds the PC ‘B’ MAC to the CAM table for Port 3.