VMware vDefend Distributed IDS/IPS performs deep packet inspection right at the virtual machine's network interface card (vNIC). To intercept this traffic at the hypervisor kernel level, it requires the advanced networking hooks and abstraction provided by modern virtual switches.

It fully supports workloads connected to modern NSX Overlay Segments, NSX VLAN Segments, and traditional vSphere Distributed Switches (vDS). However, legacy vSphere Standard Switches (vSS) lack the centralized management plane, distributed architecture, and necessary kernel APIs required to enforce NSX-based distributed security features. Therefore, you cannot implement Distributed IDS on a standard switch portgroup.