Configuring Dual-Homed FEX modules
Lately at work I've been testing dual-homed FEX connectivity in an Active/Standby configuration on the Nexus 9300 platform. Dual-Homed FEX are only supported on specific Nexus switch models and NX-OS versions etc and depending on the Nexus platform in various configuration types. There's a Cisco article on which topologies are supported on which platforms that can be found here.