$VCHost = Read-Host "Please enter the hostname or IP of a VirtualCenter instance: "
$VCUser = Read-Host "User ID: "
$VCPassword = Read-Host "Password: "

# Get all the custom defined portgroups from the VC instance and build a list of unique portgoups names and vlan ids

# Define the Array (Dictionary actually) of PortGroups we want to add to the host
$PortGroupsToAdd = @{}

$VC = Get-VC -Server $VCHost -User $VCUser -Password $VCPassword
$ESXHosts = Get-VMHost

Write-Host "Connected to VirtualCenter " $VCHost
Write-Host "Found the following ESX hosts... "
Write-Host $ESXHosts
Write-Host "`nLooking for Port Groups configured on each host...`n"

foreach ($ESXHost in $ESXHosts){

$VirtualSwitches = Get-VirtualSwitch -VMHost $ESXHost
foreach ($VirtualSwitch in $VirtualSwitches){
$VirtualPortGroups = Get-VirtualPortGroup -VirtualSwitch $VirtualSwitch
foreach ($VirtualPortGroup in $VirtualPortGroups){
# Don't do anything for the console, kernel, or default VM portgroups
if (($VirtualPortGroup).Name -ne "Service Console") {
if (($VirtualPortGroup).Name -ne "VMkernel") {
if (($VirtualPortGroup).Name -ne "VM Network") {
$TemporaryArrayofNames = @()
foreach ($prtgroupinthearray in $PortGroupsToAdd.Keys){
$TemporaryArrayofNames += $PortGroupsToAdd[$prtgroupinthearray].Name
}

$PortGroupName = ($VirtualPortGroup).Name
$IsItInTheArray = $TemporaryArrayofNames -contains $PortGroupName

Write-Host "Found Port Group $PortGroupName on ESX Host $ESXHost"

if ($TemporaryArrayofNames -contains $PortGroupName){

# Check to see if all the info of this discovered portgroup matches what I already know

if ($PortGroupsToAdd[$PortGroupName].Key -ne $VirtualPortGroup.Key){
Write-Host "I know the network, but the key doesnt match what i know"
Write-Host `n
Write-Host "Please Pick the correct key from those below..."
Write-Host "1 - " $PortGroupsToAdd[$PortGroupName].Key "<-- What I had"
Write-Host "2 - " $VirtualPortGroup.Key "<-- What I found on " $ESXHost
Write-Host `n
$RealKey = Read-Host "Enter 1 or 2 to resolve the conflict and continue"
if ($RealKey -eq "2"){
$PortGroupsToAdd[$PortGroupName].Key = $VirtualPortGroup.Key
}}
if ($PortGroupsToAdd[$PortGroupName].VLanId -ne $VirtualPortGroup.VLanId){
Write-Host "I know the network, but the VLanId doesnt match what i know"
Write-Host `n
Write-Host "Please Pick the correct VLanId from those below..."
Write-Host "1 - " $PortGroupsToAdd[$PortGroupName].VLanId "<-- What I had"
Write-Host "2 - " $VirtualPortGroup.VLanId "<-- What I found on " $ESXHost
Write-Host `n
$RealKey = Read-Host "Enter 1 or 2 to resolve the conflict and continue"
if ($RealKey -eq "2"){
$PortGroupsToAdd[$PortGroupName].VLanId = $VirtualPortGroup.VLanId
}}
if ($PortGroupsToAdd[$PortGroupName].VirtualSwitchName -ne $VirtualPortGroup.VirtualSwitchName){
Write-Host "I know the network, but the VirtualSwitchName doesnt match what i know"
Write-Host `n
Write-Host "Please Pick the correct VirtualSwitchName from those below..."
Write-Host "1 - " $PortGroupsToAdd[$PortGroupName].VirtualSwitchName "<-- What I had"
Write-Host "2 - " $VirtualPortGroup.VirtualSwitchName "<-- What I found on " $ESXHost
Write-Host `n
$RealKey = Read-Host "Enter 1 or 2 to resolve the conflict and continue"
if ($RealKey -eq "2"){
$PortGroupsToAdd[$PortGroupName].VirtualSwitchName = $VirtualPortGroup.VirtualSwitchName
}}

Write-Host "I already know about this network. Ignoring it.`n"
}
else {
Write-Host "This network name is new to me, I will add it to my list."

$PortGroupName = $VirtualPortGroup.Name
$PortGroupKey = $VirtualPortGroup.Key
$PortGroupVLanId = $VirtualPortGroup.VLanId
$PortGroupVirtualSwitchName = $VirtualPortGroup.VirtualSwitchName

Write-Host "Port Group Name ............ $PortGroupName"
Write-Host "Port Group Key ............. $PortGroupKey"
Write-Host "Port Group VLanId .......... $PortGroupVLanId"
Write-Host "Port Group VirtualSwitch ... $PortGroupVirtualSwitchName`n"

$PortGroupsToAdd.$PortGroupName = $VirtualPortGroup

}}}}}}}

$TemporaryArrayofNames = @()
foreach ($prtgroupinthearray in $PortGroupsToAdd.Keys){
$TemporaryArrayofNames += $PortGroupsToAdd[$prtgroupinthearray].Name
}

# Ok, I finally have my list of networks I want to make sure are on my ESX hosts in the VC instance.
# Now I need to go through each host and make sure that it has all the networks on my list.

foreach ($ESXHost in $ESXHosts){
Write-Host "Now Configuring $ESXHost"
$ESXVirtualSwitches = Get-VirtualSwitch -VMHost $ESXHost
foreach ($ESXVirtualSwitch in $ESXVirtualSwitches){
$ESXVirtualPortGroups = Get-VirtualPortGroup -VirtualSwitch $ESXVirtualSwitch
$TemporaryArrayofESXPortGroupNames = @()
foreach ($ESXVirtualPortGroup in $ESXVirtualPortGroups){
$TemporaryArrayofESXPortGroupNames += $ESXVirtualPortGroup.Name
}

# Go through our list of PortGroups we want and add the ones appropriate for this virtual switch that don't exist already

foreach ($prtgroupinthearray in $PortGroupsToAdd.Keys){
if ($TemporaryArrayofESXPortGroupNames -notcontains $PortGroupsToAdd[$prtgroupinthearray].Name){
if ($PortGroupsToAdd[$prtgroupinthearray].VirtualSwitchName -eq $ESXVirtualSwitch.Name){

New-VirtualPortGroup -VirtualSwitch $ESXVirtualSwitch -Name $PortGroupsToAdd[$prtgroupinthearray].Name -VLanId $PortGroupsToAdd[$prtgroupinthearray].VLanId

}}}
# Bring back in our newly updated list of VLans
$ESXVirtualPortGroups = Get-VirtualPortGroup -VirtualSwitch $ESXVirtualSwitch

# Now go through each one and make sure it is configed for the right VLanId
foreach ($ESXVirtualPortGroup in $ESXVirtualPortGroups){

# Check to see if this portgroup already exists on the ESX host
# If it does exist, then we want to set the VLanId correctly

$PortGroupName = ($ESXVirtualPortGroup).Name

if ($TemporaryArrayofNames -contains $PortGroupName){
if ($ESXVirtualPortGroup.VirtualSwitchName -eq $PortGroupsToAdd[$PortGroupName].VirtualSwitchName){
if ($ESXVirtualPortGroup.VLanId -ne $PortGroupsToAdd[$PortGroupName].VLanId){
Write-Host "Found PortGroup $PortGroupName on ESX Host $ESXHost using VirtualSwitch $ESXVirtualSwitch"
Write-Host "But the VLanIds don't match up!"
Write-Host "Setting values for PortGroup $PortGroupName on ESX Host $ESXHost"
Set-VirtualPortGroup -VirtualPortGroup $ESXVirtualPortGroup -VLanId $PortGroupsToAdd.$PortGroupName.VLanId

}}}

}}}

Write-Host "`nDone configuring networks for VirtualCenter $VCHost"