Sets DNS server based on octet in AWS

set-dnsServer.ps1

<##>

param (
    [int]$WhichOctet,
    [int]$Zone1_OctetValue,
    [int]$Zone2_OctetValue,
    $DNSZone1_server,
    $DNSZone2_server  
)

function Get-AWSIP
    {        Invoke-WebRequest http://169.254.169.254/latest/meta-data/local-ipv4    }

function Get-Interface($IPaddr)
    {        Get-NetIPAddress | Where IPAddress -EQ $IPaddr     }
    
function Set-DnsClientServer($Zone1_OctetValue,$Zone2_OctetValue,$DNSZone1_server,$DNSZone2_server,$Interface_index,$octet_value)
    {
       if ($octet_value -eq  $Zone1_OctetValue)
            {   #Set-DnsClientServerAddress -InterfaceIndex $interface_index -ServerAddresses ($DNSZone1_server,$DNSZone2_server) 
                "Zone 1"
            }
        elseif ($octet_value -eq $Zone2_OctetValue)
            {    
                #Set-DnsClientServerAddress -InterfaceIndex $interface_index -ServerAddresses ($DNSZone2_server,$DNSZone1_server)
                "Zone 2"
            }
        else {"ERROR:- No Match"}
    }

$ip  = Get-AWSIP
$interface = get-interface($ip.content)
$octet_value = $ip.content.split(".")[$WhichOctet -1]

write-host "IP:" $ip.content "-- octet:" $octet_value "-- interface:" $interface.InterfaceIndex

Set-DnsClientServer -Zone1_OctetValue $Zone1_OctetValue `
                    -Zone2_OctetValue $Zone2_OctetValue `
                    -DNSZone1_server $DNSZone1_server `
                    -DNSZone2_server $DNSZone2_server `
                    -Interface_index $interface.InterfaceIndex `
                    -octet_value $octet_value