Unless you already have a licensed copy of the Cisco Nexus 1000V, then you can download the evaluation here: http://www.cisco.com/go/1000veval
Note: you will need to register for a Cisco account in order to download the evaluation.
vSphere environment with vCenter.
Note: I’m using my vSphere 5 lab for this exercise but vSphere 4.1 will do fine.
At least one ESX/ESXi host, preferably two or more!
If you are using a lab environment and don’t have the physical hardware available then create a virtual ESXi server (this post by VCritical details how to do this).