Wednesday, 16 August 2017

Creating an internal / NAT'd network using a vSwitch on Server 2012 / 2016

We'll firstly need to install the Hyper V role - since we'll require the management tools in order to create our interface:

Install-WindowsFeature Hyper-V –IncludeManagementTools
Install-WindowsFeature Routing -IncludeManagementTools

However I had the following message returned when attempting installation:

Hyper-V cannot be installed: A hypervisor is already running.

As I was running under VMWare I had to install the feature using a slightly different method (bare in mind we have no intention of using the Hyper V hypervisor - however we do want to take advantage of the virtualized networking capabilities.

So instead I installed Hyper with:

Enable-WindowsOptionalFeature –Online -FeatureName Microsoft-Hyper-V –All -NoRestart

and the management tools with:

Install-WindowsFeature RSAT-Hyper-V-Tools -IncludeAllSubFeature

Ensure the NAT routing protocol is available to RRAS - 'Administrative Tools' >> 'Routing and Remote Access' >> Expand the following: Server, IPv4 and right hand click on general and select 'New Routing Protocol' >> Select NAT

We can now create our new virtual switch with:

New-VMSwitch -SwitchName "SwitchName" -SwitchType Internal

and assign the interface with an IP:

New-NetIPAddress -IPAddress -PrefixLength 16 -InterfaceIndex <id>

(You can get the associated interface index with: Get-NetAdapter)

At this point you won't be able to ping any external hosts from that interface - we can verify that using the '-S' switch with ping:

ping -S

So - we'll need to enable NAT with:

New-NetNat -Name "NATNetwork" -InternalIPInterfaceAddressPrefix

and then attempt to ping from the interface again:

ping -S


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