Basics of SCVMM 2012R2/2016 networking – simplified

This post is an attempt at explaining SCVMM networking concepts in the simplest way possible. From what I’ve observed, most articles (MS official and not) out there go in depth and given the convoluted nature of SCVMM networking it’s easy to flounder in the sheer volume of information. Without further ado..

First, leave your vSphere hat aside. My colleague, Pravesh Khanna, @praveshsk2012, gave me this great advice. Forget vSphere networking, forget it’s easy. Start afresh here.

Next, understand that not all of SCVMM networking sits conveniently in an area in the console labelled – Networking. You configure it in the Networking area but assign it to hosts by going to each host or you PoSh it.

With the above pre-reqs out of the way, you’d create the bits in the following order:

1. Logical Networks – these are said to be the foundation of networking. Think of logical networks as an abstraction of the physical topology of the environment. This is where you tell the system to associate VLANs and IP subnets to particular hosts or host groups. Say you have a 4 racks of hosts in Datacenter A collectively in a folder called WorkloadCluster, 2 racks provide connectivity to Front-end Production Web VMs in VLAN 100. You create:

SCVMM_Networking_4

Script:

$logicalNetwork = New-SCLogicalNetwork -Name “FrontEndWebTier_100” -LogicalNetworkDefinitionIsolation $false -EnableNetworkVirtualization $false -UseGRE $false -IsPVLAN $false

$allHostGroups = @()
$allHostGroups += Get-SCVMHostGroup -ID “09ba4092-e408-48f7-af31-7a33b77b73d5”
$allSubnetVlan = @()
$allSubnetVlan += New-SCSubnetVLan -Subnet “10.0.100.0/24” -VLanID 100

New-SCLogicalNetworkDefinition -Name “FrontEndWebTier_100” -LogicalNetwork $logicalNetwork -VMHostGroup $allHostGroups -SubnetVLan $allSubnetVlan -RunAsynchronously

2. Logical Switches – just for some context, these are what we’d call distributed switches in vSphere. You create once and apply to all/relevant hosts as needed for a consistent feature set across all of them. Pretty handy. Now a logical switch is essentially a collection of capabilities. These capabilities are offered by:

  • port profiles, of which there are two types
    • uplink port profile – physical NICs (pNICs) of hosts
      • provides NIC teaming
        • failover to surviving adapter(s)
      • do note you still only choose multiple pNICs when assigning logical switches to hosts

SCVMM_Networking_5

SCVMM_Networking_6

    • virtual network adapter port profile – the adapters VMs connect to
      • provides virtual adapter capabilities like
        • direct access to physical adpaters (SR-IOV)
        • guest teaming, DHCP guard
        • network QoS – so particular VMs can only use a minimum and maximum bandwidth of the physical NIC

SCVMM_Networking_7

  • port classifications – these are only labels, no more, but you must create them with similar names as you’d give to port profiles

SCVMM_Networking_8

  • switch extensions – for monitoring, security etc (we wont talk about these since they are not essential to successful operation)

So the logical switch would look like:

SCVMM_Networking_9, and

SCVMM_Networking_10_new

3. Assign Logical Switch to hosts. This is the final step in the process.

SCVMM_Networking_11

Quite bizarre is the option to go with a ” New Virtual Switch” and then choose the Logical Switch we created above. There should’ve been a “Choose Existing Virtual Switch”. Anyways, this is where you choose multiple pNICs for redundancy. The virtual adapters VMs will hook up to come down from the Logical Switch. If you want more labels, create them in the Logical Switch.

4. Then when you go to create a new VM, you choose the VM Network the VM should connect to:

SCVMM_Networking_12

I hope this clears things somewhat for those folks who found this difficult to grasp. I sure found this a little confusing coming in with a predominantly vSphere background. If there’s a question, feel free to drop a comment below.

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