What is vNIC, VMKNIC, PortGroups, Uplink Ports, vPorts and VMXNET3 Adapter




Virtual Networking is one of the Key components of Datacenter. If all your Critical VMs running on highly redundant & high speed SAN or Ethernet Network but if VMs can’t communicate with each other then everything is useless.

From Functioning perspective, Virtual Network in VMware is similar to Physical Networks. Like Physical networking, Virtual networking is also exercises TCP/IP stack so nothing is changed underneath.

But Virtual networking has introduced many new components or its complex terminology which is sufficient enough to confuse any new admin or anyone who is trying to familiar with VMware Networking.

In this post, I will try to make you guys familiar with VMware Networking components, Its terminology and significance of each Networking Component.






Virtual network adapter is similar to Network Interface Card (NIC) in physical networking. This Virtual Network Adapters are used by Virtual Machines or VMkernel TCP/IP stack to communicate with other virtual Machines or Physical Network Devices.


This Virtual Network Adapter is used by Virtual Machines to communicate with other network devices in Virtual or Physical environment.

There are four types of Virtual Adapters available for VMs:


This vNIC adapter is exact simulation of Intel 1G 82545EM ethernet Adapter. This vNIC is used for both 32bit and 64bit Virtual Machines and available since WinXP.
This vNIC driver doesn’t required vmware-tools installation in VMs so its default driver enabled for most of Operating systems.


This vNIC adapter is Intel newer generation adapter, the 1G Intel 82574 & its only available on hardware version 8 or higher. It’s a default vNIC for Windows 8 and newer guest OS.


Vmxnet2 adapter is para-virtualized adapter designed by VMware for higher performance. Since its’a para-virtualized adapter so it only comes with vmware-tools package. VM using vmxnet2 adapter should have vmware-tools installed in it.
This Adapter provides optimized performance by supporting features like Jumbo Frame , Hardware Offload techniques like TSO, CSO etc..


Vmxnet3 is the next generation of ParaVirtualized NIC designed for performance. This vmxnet3 is a 10 Gb Virtual NIC. Vmxnet3 is supported by all Operating systems and shipped with vmware-tools.Vmxnet3 is much faster than e1000 or e1000e adapter.
Its highly optimized adapter designed for better performance in virtual machine and support advanced driver features like Multique support, RSS, LRO, TSOIPv6, CSOIPv6 etc..


Its a specialized Vmware Paravirtualized adapter used by Vmkernel TCP/IP stack. This Specialized adapter has its own MAC address and used to connect the Vmkernel to services that it provides.

Vmkernel NIC provides mainly 5 services :

    1. Management Connectivity

    2. IP Storage

    3. NFS connectivity

    4. vMotion

    5. Fault Tolerance


Its again a specialized Paravirtualized adapter similar to vmxnet that was used only by the ESX service console in ESX Product. Since Service Console has been removed in ESXi so vswif doesn’t exist anymore.


vPorts on a virtual switch provide logical connection points among virtual devices and between virtual and physical devices. You can think of them as virtual RJ-45 connectors.
Each virtual switch can have upto 1016 active ports with a max limit of 4096 ports per switch.


Portgroups are templates used to configure persistent network policies for virtual ethernet adapters. Group of Virtual Machine share common network configuration can be mapped same Portgroup.


Physical Ethernet Adapter referred as Uplink in Virtual Networking. Uplink serve as bridges between Virtual and Physical Network. Virtual Ports of vSwitch connected to Uplinks are called Uplink Ports.

A Single ESX host can have maximum of 32 uplinks.



vSphere Standard vSwitch is layer2 software switch that resides in Vmkernel and provides traffic management for Vms and Vmkernel traffic. Control plane and IO Plane sits in ESXi Host only so user needs to manage standard vSwitches individually. In Short, there is no centralized management for vSphere Standard Switches.



Vsphere Distributed Switch is centralized Layer2 switch provides traffic management for Vms and Vmkernel traffic. Distributed switches are centralized switch spans across multiple ESXi hosts. This Distributed switch can only be managed by vCenter Server.





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VMware Solution Architect
I am VMware Solution Architect with 10+ Years of enriching experience in Datacenter Virtualization Technologies, Storage Area Networks and Software Defined Datacenter, Networking and Storage.
I hold Numerous certification including RHCE, CCNA, VCP4.0, VCP5.1, VCP5.5, vCloud and EMC certification.
While spending countless hours exploring the product inside and out and learning everything about it, Eventually I discovered my passion for teaching and helping others learn from my knowledge and experience so turned to Trainer cum Blogger to educate every single person keen to learn Virtualization.

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