Using the vSphere Web Client to display Software iSCSI Initiator properties reveals that one of two configured paths is Not Used. The ESXi syslog events are as shown: What is the root cause of the pro

For Software iSCSI multipathing, each bound VMkernel adapter must reside on the same IP subnet as the iSCSI target so that layer-3 routing is not required. If vmk3 is on a different subnet than the iSCSI server, ESXi cannot establish a session over that path, and the path status is reported as 'Not Used' rather than 'Active' or 'Standby'.

A path in 'Not Used' status is not a standby path waiting for failover - it indicates the path is excluded from use entirely, not that it is passively ready to activate on vmk1 failure.

Lost network connectivity would typically show the path as 'Dead' or 'Lost Communication', not 'Not Used', which specifically indicates the path is administratively or logically excluded.

iSCSI port binding requires each VMkernel adapter to be on a separate vSwitch or at least a separate physical uplink for network isolation, but being on a different vSwitch from vmk1 would not by itself cause 'Not Used' status - subnet mismatch is the direct cause.