- As many vCenter you have, need to deploy that number of NSX Manager.
- Provides management capabilities
- Associates NSX with vCenter Server
- Gives an User Interface to manage and configure NSX environment
- Embedded in NSX Manager
- Deploy from NSX Manager
- Minimum and Maximum 3 NSX Controller per NSX Manager
- It helps us in routing and switching
- It maintains 4 different tables.
- 3 tables it maintains related to switching is;
- Keeps MAC address of VMs.
- W1 is a virtual machine which has an adaptor. And this virtual machine will power on this host.
- Host has netcpad.
- Netcpad will tell controller that this VM has powered on to this host.
- Same will be for other virtual machines as well.
- When you know IP address but not name.
- Address resolution protocol.
- Keeps IP of Virtual machine.
- Keeps VTEP information of ESXi host.
- VMK port information of VTEP interface.
Underlay network devices that you have, are they supporting multicast protocol?
1st Factor - TOR, Spine, and Physical router, does they support multicasting. If not, then you need NSX Controller.
2nd Factor - Is the underlay topology support multicast or not? If not, then NSX controller is required.
3rd Factor – Do you want to use Distributed Logical Router (DLR)? If yes, then you need NSX controller.
4th Factor - If you want to define Software defined L2 bridging, then you need NSX controller.
If your physical topology in underlay network, if all devices does support multicast IP address to do one to many communications, they you may NOT require NSX controller.
As a best practice, we should always deploy NSX Controller.