Ondrej Sevecek's English Pages

# Note: we will reconfigure all the NICs that currently
#       contain at least one of the $currentPossibleDNSs DNS server IPs 
#       among the list of its configured DNS servers. We do not touch
#       any other NICs to be on the safe side agains WiFis and VPNs
$currentPossibleDNSs = @('10.10.0.18', '10.10.0.11')

# Note: we will configure the NICs with exactly the following
#       list of DNS server IPs which gets reset to this list in effect
$newDNS = @('10.10.0.12', '10.10.0.11', '10.10.0.15')

#
#

[object[]] $nics = gwmi win32_networkadapterconfiguration | ? { $_.DNSServerSearchOrder.Count -gt 0 }

foreach ($oneNic in $nics) {

  [bool] $matches = $false

  foreach ($oneCurrentDNS in $currentPossibleDNSs) {
    
    if ($oneNic.DNSServerSearchOrder -contains $oneCurrentDNS) {

      $matches = $true
      break
    } 
  }

  if ($matches) {

    Write-Host ('One found NIC: ip = {0} | {1} | dns = {2}' -f ($oneNic.IPAddress -join ','), $oneNic.Description, ($oneNic.DNSServerSearchOrder -join ','))

    $res = $oneNic.SetDNSServerSearchOrder($newDNS)
    Write-Host ('Reconfigured: {0}' -f $res.ReturnValue)

    if ($res.ReturnValue -ne 0) {

      throw ('Cannot reconfigure search order on NIC: #{0} | error = {1}' -f $oneNic.InterfaceIndex, $res.ReturnValue)
    }
  }
}