juchestyle
Commander
Commander

Two Easy Questions about Unicast and Hybrid Mode

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VMware recommends VXLAN hardware offloading capable NICs correct?

If that is the case is Hybrid mode the correct choice as it is designed to offload to physical network?

Second question (First was rhetorical), Is Unicast purpose built for NSX, as in it was designed specifically for NSX.  Or, does it just work well for what NSX is and is therefore the right choice for usage?

Working on my certification, hopefully going to take it at VMworld!!!

Kaizen!
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lhoffer
VMware Employee
VMware Employee

The VXLAN hardware offload done on NICs is different from the "Hybrid" and multicast Transport Zone options.  The VXLAN NIC offload is where the NIC will handle VXLAN encapsulation/decapsulation of frames rather than having it done by the CPU.  The hybrid/multicast options for Transport Zones/Logical Switches refers to how NSX will flood traffic on a VXLAN for broadcast, unknown unicast, and multicast so that instead of creating a copy of the frame for each host with VMs in that VXLAN (as happens in unicast mode) it'll send traffic as a single L3 multicast packet (in multicast mode) or a single L2 unicast frame for hosts on the local segment and then let the upstream router or switch handle replication to the multicast listeners.  The VMware® NSX for vSphere Network Virtualization Design Guide ver 3.0​ covers this in a lot more detail on page 35 as well.

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lhoffer
VMware Employee
VMware Employee

The VXLAN hardware offload done on NICs is different from the "Hybrid" and multicast Transport Zone options.  The VXLAN NIC offload is where the NIC will handle VXLAN encapsulation/decapsulation of frames rather than having it done by the CPU.  The hybrid/multicast options for Transport Zones/Logical Switches refers to how NSX will flood traffic on a VXLAN for broadcast, unknown unicast, and multicast so that instead of creating a copy of the frame for each host with VMs in that VXLAN (as happens in unicast mode) it'll send traffic as a single L3 multicast packet (in multicast mode) or a single L2 unicast frame for hosts on the local segment and then let the upstream router or switch handle replication to the multicast listeners.  The VMware® NSX for vSphere Network Virtualization Design Guide ver 3.0​ covers this in a lot more detail on page 35 as well.

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bayupw
Leadership
Leadership

As mentioned by Luke in previous reply, there should be no relations between physical NIC offload (VXLAN TSO) and control plane options in my opinion.

There is a good blog post by Dmitri Kalintsev on VXLAN Control Plane options here: NSX for vSphere: VXLAN Control Plane modes explained | Telecom Occasionally

Bayu Wibowo | VCIX6-DCV/NV
Author of VMware NSX Cookbook http://bit.ly/NSXCookbook
https://github.com/bayupw/PowerNSX-Scripts
https://nz.linkedin.com/in/bayupw | twitter @bayupw
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Techstarts
Expert
Expert

Working on my certification, hopefully going to take it at VMworld!!!

Best of luck for your exam.(VCP-NV?)

Second question (First was rhetorical), Is Unicast purpose built for NSX, as in it was designed specifically for NSX.  Or, does it just work well for what NSX is and is therefore the right choice for usage?

It is just there for ages. To my knowledge nothing is purpose built

With Great Regards,
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