Labworks 2:5-8 – Get-Me -ConvergedSwitching -For “Hyper-V” | Now-Please

Hello Labworks fans, detractors and partisans alike, hope you had a nice Easter / Resurrection / Agnostic Spring Celebration weekend.

Last time on Labworks 2:1-4, we looked at some of the awesome teaming options Microsoft gave us with Server 2012 via its multiplexor driver. We also made the required configuration adjustments on our switch for jumbo frames & VLAN trunking, then we built ourselves some port channel interfaces flavored with LACP.

I think the multiplexor driver/protocol is one of the great (unsung?) enhancements of Server 2012/R2 because it’s a sort of pre-virtualization abstraction layer (That is to say, your NICs are abstracted & standardized via this driver before we build our important virtual switches) and because it’s a value & performance multiplier you can use on just about any modern NIC, from the humble RealTek to the Mighty Intel Server 10GbE.

But I’m getting too excited here; let’s get back to the curriculum and get started shall we?


5.  Understand what Microsoft’s multiplexor driver/LBFO has done to our NICs

6. Build our Virtual Machine Switch for maximum flexibility & performance

7. The vEthernets are Coming

8. Next Steps: Jumbo frames from End-to-end and performance tuning


Lab 2 - Daisetta Labs overview

2:5 Understand what Microsoft’s Multiplexor driver/LBFO has done to our NICs

So as I said above, the best way to think about the multiplexor driver & Microsoft’s Load Balancing/Failover tech is by viewing it as a pre-virtualization abstraction layer for your NICs. Let’s take a look.

Our Network Connections screen doesn’t look much different yet, save for one new decked-out icon labeled “Daisetta-Team:”


Meanwhile, this screen is still showing the four NICs we joined into a team in Labworks 2:3, so what gives?

A click on the properties of any of those NICs (save for the RealTek) reveals what’s happened:

Egads! My Intel NIC has been neutered by LBFO
Egads! My Intel NIC has been neutered by LBFO

The LBFO process unbinds many (though not all) settings, configurations, protocols and certain driver elements from your physical NICs, then binds the fabulous Multiplexor driver/protocol to the NIC as you see in the screenshot above.

In the dark days of 2008 R2 & Windows core, when we had to walk up hill to school both ways in the snow I had to download and run a cmd tool called nvspbind to get this kind of information.

Fortunately for us in 2012 & R2, we have some simple cmdlets:


So notice Microsoft has essentially stripped “Ethernet 4” of all that would have made it special & unique amongst my 4x1GbE NICs; where I might have thought to tag a VLAN onto that Intel GbE, the multiplexor has stripped that option out. If I had statically assigned an IP address to this interface, TCP/IP v4 & v6 are now no longer bound to the NIC itself and thus are incapable of having an IP address.

And the awesome thing is you can do this across NICs, even NICs made by separate vendors. I could, for example, mix the sacred NICs (Intel) with the profane NICs (RealTek)…it don’t matter, all NICs are invited to the LBFO party.

No extra licensing costs here either; if you own a Server 2012 or 2012 R2 license, you get this for free, which is all kinds of kick ass as this bit of tech has allowed me in many situations to delay hardware spend. Why go for 10GbE NICs & Switches when I can combine some old Broadcom NICs, leverage LACP on the switch, and build 6×1 or 8x1GbE Converged LACP teams?

LBFO even adds up all the NICs you’ve given it and teases you with a calculated LinkSpeed figure, which we’re going to hold it to in the next step:

4GbS LACP team sounds great, but is it really 4Gb/s?
4GbS LACP team sounds great, but is it really 4Gb/s?

2:6 Build our Virtual Machine Switch for maximum flexibility & performance

If we just had the multiplexor protocol & LBFO available to us, it’d be great for physical server performance & durability. But if you’re deploying Hyper-V, you get to have your LBFO cake and eat it too, by putting a virtual switch atop the team.

This is all very easy to do in Hyper-V manager. Simply right click your server, select Virtual Switch Manager, make sure the Multiplexor driver is selected as the NIC, and press OK.

Bob’s your Uncle:


But let’s go a bit deeper and do this via powershell, where we get some extra options & control:

PS C:usersjeff.DAISETTALABS> new-vmswitch -NetAdapterInterfaceDescription “Microsoft Network Adapter Multiplexor Driver” -AllowManagementOS 1 -MinimumBandwidthMode Weight -name “Daisetta-Converged”

Let’s go through each of these:

  • New-vmswitch : the cmdlet we’re invoking to build the switch. Run get-help new-vmswitch for a rundown of the cmdlet’s structure & options
  • -NetAdapterInterfaceDescription : here we’re telling Windows which NIC to build the VM Switch on top of. Get the precise name from Get-NetAdapter and enclose it in quotes
  • -Allow ManagementOS 1 : Recall the diagram above. This boolean switch (1 yes, 0 no) tells Windows to create the VM Switch & plug the Host/Management Operating System into said Switch. You may or may not want this; in the lab I say yes; at work I’ve used No.
  • -Minimum Bandwidth Mode Weight: We lay out the rules for how the switch will apportion some of the 4Gb/s bandwidth available to it. By using “Weight,” we’re telling the switch we’ll assign some values later
  • Name: Name your switch

A few seconds later, and congrats Mr. Hyper-V admin, you have built a converged virtual switch!

2:7 The vEthernets are Coming

Now that we’ve built our converged virtual switch, we need to plug some things into it. And that starts on the physical host.

If you’re building a Hyper-V cluster or stand-alone Hyper-V host with VMs on networked storage, you’ll approach vEthernet adpaters differently than if you’re building Hyper-V for VMs on attached/internal storage or on SMB 3.0 share storage. In the former, you’re going to need storage vEthernet adpters; in the latter you won’t need as many vEthernets unless you’re going multi-channel SMB 3.0, which we’ll cover in another labworks session.

I’m going to show you the iSCSI + Failover Clustering model.

In traditional Microsoft Failover Clustering for Virtual Machines, we need a minimum of five discrete networks. Here’s how that shakes out in the Daisetta Lab:


Network Name, VLAN ID, Purpose, Notes

Management, 1, Host & VM management network, You can separate the two if you like

CSV, 14, Host Cluster & communication and coordination, Important for clustering Hyper-V hosts

LM, 15, Live Migration network, When you must send VMs from broke host to host with the most LM is there for you

iSCSI 1-3, 11-13, Storage, Soemwhat controversial but supported


Now you should be connecting that dots: remember in Labworks 2:1, we built a trunked port-channel on our Cisco 2960S for the sole purpose of these vEthernet adapters & our converged switch.

So, we’re going to attach tagged vethernet adapters to our host via powershell. Pay attention here to the “-managementOS” tag; though our Converged switch is for virtual machines, we’re using it for our physical host as well.

You can script his out of course (and VMM does that for you), but if you just want to copy paste, do it in this order:

  • Add the vEthernets
add-vmnetworkadapter -managementos -name CSV -switchname Daisetta-converged
add-vmnetworkadapter -managementos -name iSCSI-1 -switchname Daisetta-converged add-vmnetworkadapter -managementos -name iSCSI-2 -switchname Daisetta-converged
add-vmnetworkadapter -managementos -name iSCSI-3 -switchname Daisetta-converged
add-vmnetworkadapter -managementos -name LM -switchname Daisetta-converged
  • Tag those vEthernets!
Set-VMNetworkAdapterVlan -ManagementOS -Access -VlanId 15 -VMNetworkAdapterName LM
Set-VMNetworkAdapterVlan -ManagementOS -Access -VlanId 14 -VMNetworkAdapterName CSV
Set-VMNetworkAdapterVlan -ManagementOS -Access -VlanId 13 -VMNetworkAdapterName iSCSI-3
Set-VMNetworkAdapterVlan -ManagementOS -Access -VlanId 12 -VMNetworkAdapterName iSCSI-2
Set-VMNetworkAdapterVlan -ManagementOS -Access -VlanId 11 -VMNetworkAdapterName iSCSI-1
  • Now set IPs
New-NetIPAddress -IPAddress -InterfaceAlias "vEthernet (CSV)" -AddressFamily IPv4 -PrefixLength 24
New-NetIPAddress -IPAddress -InterfaceAlias “vEthernet (LM)” -AddressFamily IPv4 -PrefixLength 24
New-NetIPAddress -IPAddress -InterfaceAlias "vEthernet (iSCSI-3)" -AddressFamily IPv4 -PrefixLength 24
New-NetIPAddress -IPAddress -InterfaceAlias "vEthernet (iSCSI-2)" -AddressFamily IPv4 -PrefixLength 24
New-NetIPAddress -IPAddress -InterfaceAlias "vEthernet (iSCSI-1)" -AddressFamily IPv4 -PrefixLength 24

Notice we didn’t include a Gateway in the New-NetIPAddress cmdlet; that’s because when we built our Virtual Switch with the “-managementOS 1” switch attached, Windows automatically provisioned a vEthernet adapter for us, which either got an IP via DHCP or took an apipa address.

So now we have our vEthernets and their appropriate VLAN tags:

Ignore the DMZ vEthernet for now. Notice Daisetta-Converged, our VM Switch, is seen as a VMNetworkAdapter and is untagged. In my lab, this interface functions as my Host Management interface. In a production scenario, you’ll probably use separate vEthernet adapters for Host Management and not expose the switch itself to the management OS








2:8: Next Steps : Jumbo Frames from end-to-end & Performance Tuning

So if you’ve made it this far, congrats. If you do nothing else, you now have a converged Hyper-V virtual switch, tagged vEthernets on your host, and a virtualized infrastructure that’s ready for VMs.

But there’s more you can do; stay tuned for the next labworks post where we’ll get into jumbo frames & performance tuning this baby so she can run with all the bandwidth we’ve given her.

Links/Knowledge/Required Reading Used in this Post:

Resource, Author, Summary
New-VMSwitch Technet, Microsoft, Always good to have Technet reference
Building a Converged Fabric with Server 2012, Hans “The Hyper-Dutchman” Vredevoort, A 2012 post which helped me when I was struggling through 2008 R2 to 2012 Hyper-V migration

Hyper-V 3.0 Converged Networks with Force 10 and DCB, Dell, Neat Wiki & diagram with iSCSI as separate virtual switch but with DCB




2 thoughts on “Labworks 2:5-8 – Get-Me -ConvergedSwitching -For “Hyper-V” | Now-Please

  1. Hi, I can’t find the next lab with ‘Jumbo frames and performance tuning’. Have you been able to get jumbo working with vNICs? My 2012-R2 iscsi vNICs can’t do jumbo frames, even though these are set on the physical NIC drivers, and the vEthernet drivers (the multiplexor driver doesn’t have the option).
    And isn’t working for me…


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