Understanding Fabric Interconnect switching modes
UCS Fabric Interconnect supports two types of switching modes: End Host Mode (EHM) and standard Ethernet switching mode. The default switching mode is the End Host Mode which eliminates the use of Spanning Tree Protocol (STP) on Fabric Interconnect. The standard Ethernet switching is rarely used and it is recommended not to implement this option unless there is a use case.
Tip
Switching mode conversion is a disruptive change requiring Fabric Interconnect reboot and hence should be planned during a scheduled maintenance window.
Ethernet End Host Mode (EHM)
End Host Mode is the default mode of operation for UCS Fabric Interconnect Ethernet connectivity. In this mode, UCS Fabric Interconnect is presented to the northbound LAN switch as an end host with many adapters. STP is not configured on the uplink switch ports. Since there is no STP, all FI ports are in the forwarding state irrespective of the northbound topology. This means that data traffic...
