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rickd33
Contributor
Contributor

CDO Mode Questions

After looking at CDO mode I want to look into the CDO switch that is created and view the VTEP list etc.

However, via the mgr and controllers, I'm unable to see the CDO logical switch.

What are the best commands to dive under the hood into CDO to see what it is really doing.

Questions:

  • 6.4 you enable on the manager level (Non-Cross VC). Does this mean a CDO (flooding) single switch is created for all transport zones under the controllers?
  • Once the BUM traffic for a VNI is sent over the CDO hidden switch, will traffic only go back over the correct VNI once the controller cluster connectivity is restored. Or will the global VTEP list update the correct VNI VTEP once BUM traffic is seen?
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Sreec
VMware Employee
VMware Employee

  • 6.4 you enable on the manager level (Non-Cross VC). Does this mean a CDO (flooding) single switch is created for all transport zones under the controllers?

Yes, NSX Manager creates a special CDO logical switch (4999) on the controller. The VXLAN Network Identifier (VNI) of the special CDO logical switch is unique from all other logical switches

  • Once the BUM traffic for a VNI is sent over the CDO hidden switch, will traffic only go back over the correct VNI once the controller cluster connectivity is restored. Or will the global VTEP list update the correct VNI VTEP once BUM traffic is seen?

If this is a site failure  we should enable it on Secondary site NSX manager . However Global VTEP is leverage only during failure scenarios ,All hosts in the transport zone join the CDO Logical Switch (next available VNI), and, one controller in the cluster is designated the responsibility for updating all hosts in the transport zone with the VTEP information of every other host in the transport zone. Since all hosts are members of the CDO Logical Switch, this effectively creates a Global VTEP List that is initially populated when control plane connectivity is up. If control plane connectivity is lost, this Global VTEP List will be utilised.

Cheers,
Sree | VCIX-5X| VCAP-5X| VExpert 7x|Cisco Certified Specialist
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