Get-Dns.ps1

<#
.SYNOPSIS
Looks up DNS info, given a hostname or address.

.INPUTS
System.String of host names to look up.

.OUTPUTS
System.Net.IPHostEntry of host DNS entries, or
System.String of network addresses found.

.LINK
https://msdn.microsoft.com/library/ms143998.aspx

.EXAMPLE
Get-Dns.ps1 www.google.com

HostName       Aliases AddressList
--------       ------- -----------
www.google.com {}      {172.217.10.132}
#>

[CmdletBinding()][OutputType([Net.IPHostEntry])][OutputType([string])] Param(
# A host name or address to look up.
[Parameter(Position=0,Mandatory=$true,ValueFromRemainingArguments=$true,ValueFromPipeline=$true)]
[Alias('Address','HostAddress','Name')][string[]] $HostName,
<#
Indicates that only the string versions of addresses belonging to the specified family should be returned.
"Unknown" returns all addresses.
#>
[Net.Sockets.AddressFamily] $OnlyAddresses
)

Process
{
    foreach ($h in $HostName)
    {
        $entry = [Net.Dns]::GetHostEntry($h)
        if(!$PSBoundParameters.ContainsKey('OnlyAddresses')) {$entry}
        elseif($OnlyAddresses -eq [Net.Sockets.AddressFamily]::Unspecified) {$entry.AddressList |ForEach-Object {$_.IPAddressToString}}
        else {$entry.AddressList |Where-Object AddressFamily -eq $OnlyAddresses |ForEach-Object {$_.IPAddressToString}}
    }
}