Fabric Attach Ring with ISW-Series Managed Industrial Ethernet Switches

Fabric Attach interfaces that connect to ISW-Series Managed Industrial Ethernet Switches (ISW) deploy in a ring topology.

You can enable Fabric Attach (FA) Ring Topology Change Notification (TCN) processing on an FA interface that connects to an ISW-Series switch either manually or dynamically through Auto-sense.

For more information about Auto-sense, see Auto-sense Port States.

The ISW-Series switch at the end of the ring generates a TCN BPDU packet if the connection within the ring topoloy is interrupted, and again, after the connection is restored. The switch FA interface that connects to the ISW switch processes the TCN BPDU packet. All MACs learnt on the FA interface age out. TCN BPDUs propagate across the SPBM network only if you enable MSTP-Fabric Connect Multi Homing on the switch.

If switches at the end of the ring are not virtual interswitch trunk (vIST) peers, the best practice is to enable MSTP-Fabric Connect Multi Homing on all switches that participate in the same Layer 2 VSN. Switches at the end of the ring that use virtual interswitch trunk (vIST) synchronize MAC addresses between the vIST peers. In this case, you do not need to enable MSTP-Fabric Connect Multi Homing.

For information about configuring MSTP-Fabric Connect Multi Homing, see Enable MSTP-Fabric Connect Multi Homing.

For information about ISW-Series with ring configuration, see ISW-Series Managed Industrial Ethernet Switches documentation at https://supportdocs.extremenetworks.com/support/documentation/.