VMware NSX-T Logical Switches. Part 1. What are they?

So you are ready to take the Overlay Segment Plunge but don't know what a VMware NSX-T / NSX Logical Switch or Segment is.. This is part 1 of a two part series, discussing Overlay Networks, BUM Replication, Detailed info and the Control Plane VTEP, MAC and ARP tables. We will wrap it all up with a Packet walk.. Lots of info here so get ready to have your mind blown.