Get-DNSServerList

function Get-DNSServerList {
    [CmdletBinding()]
    param ([Parameter(Mandatory, Position = 0)][Alias('Server')][string]$DomainName)
    nslookup -type=ns $DomainName 2>$null | Select-String -Pattern 'nameserver = ' | % {
        $_ -replace '.*?nameserver\s=\s(.*)', '$1'
    }
}