PowerShell – Set DHCP DNS or Set Static DNS

param(
[string]$1,
[string]$2,
[string]$3
)

function Set-DNS([string]$EnableDHCP,[string]$dns1, [string]$dns2){
$saNetAdapters = Get-NetIPInterface | Where-Object {$_.ConnectionState -eq "Connected"} 

foreach ($sNetAdapter in $saNetAdapters.ifIndex)
{
    if ($EnableDHCP -eq "eDHCP")
    {
   
       Set-DnsClientServerAddress -InterfaceIndex $sNetAdapter -ResetServerAddresses
    }
    else
    {
    Set-DnsClientServerAddress -InterfaceIndex $sNetAdapter -ServerAddresses ($dns1, $dns2)
    }
}
Clear-DnsClientCache
}

function Get-NetworkInformation(){
$computer = $env:computername

try {
    $Networks = Get-WmiObject Win32_NetworkAdapterConfiguration -ComputerName $Computer -EA Stop | ? {$_.IPEnabled}
   } catch {
        Write-Warning "Error occurred while querying $computer."
        Continue
   }
   $array = @()
   foreach ($Network in $Networks) {
    $NetworkAdapter = $Network.Description
    $IPAddress  = $Network.IpAddress[0]
    $SubnetMask  = $Network.IPSubnet[0]
    $DefaultGateway = $Network.DefaultIPGateway
    $DNSServers  = $Network.DNSServerSearchOrder
    $WINS1 = $Network.WINSPrimaryServer
    $WINS2 = $Network.WINSSecondaryServer   
    $WINS = @($WINS1,$WINS2)         
    $IsDHCPEnabled = $false
    If($network.DHCPEnabled) {
     $IsDHCPEnabled = $true
    }
    $MACAddress  = $Network.MACAddress
    $OutputObj  = New-Object -Type PSObject
    #$OutputObj | Add-Member -MemberType NoteProperty -Name ComputerName -Value $Computer.ToUpper()
    $OutputObj | Add-Member -MemberType NoteProperty -Name NetAdapter -Value $NetworkAdapter
    $OutputObj | Add-Member -MemberType NoteProperty -Name IPAddress -Value $IPAddress
    $OutputObj | Add-Member -MemberType NoteProperty -Name SubnetMask -Value $SubnetMask
    $OutputObj | Add-Member -MemberType NoteProperty -Name Gateway -Value ($DefaultGateway -join ",")      
    #$OutputObj | Add-Member -MemberType NoteProperty -Name IsDHCPEnabled -Value $IsDHCPEnabled
    $OutputObj | Add-Member -MemberType NoteProperty -Name DNSServers -Value ($DNSServers -join ",")     
    #$OutputObj | Add-Member -MemberType NoteProperty -Name WINSServers -Value ($WINS -join ",")        
    $OutputObj | Add-Member -MemberType NoteProperty -Name MACAddress -Value $MACAddress
    $array += $OutputObj
   }
   $array | Format-Table -AutoSize
}

clear

Write-Output "Current Network Information"
Get-NetworkInformation

# Enable DHCP DNS
#Set-DNS "eDHCP"

# Set Static DNS
#Set-DNS "dDHCP" "168.63.129.16" "168.62.167.9"

Set-DNS "$1" "$2" "$3"

Write-Output "Updated Network Information"
Get-NetworkInformation

Execute with

.\ChangeDNS.ps1 "eDHCP"

.\ChangeDNS.ps1 "dDHCP" "8.8.8.8" "8.8.4.4"