Tuesday, February 8, 2022

Cool PowerShell commands

 To get all A records in a zone you can do this:
Get-DnsRecord -RecordType A -ZoneName FQDN -Server ServerName

To get this into a text file:
Get-DnsRecord -RecordType A -ZoneName FQDN -Server ServerName | % {Add-Content -Value $_ -Path filename.txt}

Get-WmiObject -Namespace Root\MicrosoftDNS -Query "SELECT * FROM MicrosoftDNS_AType WHERE ContainerName='domain.com'"
WMI is good to remember when you can't download DnsShell for some reason, or if you're on an older version of Powershell that doesn't have the baked-in Cmdlets, or if you're targeting an older version of Windows Server.


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The DnsServer module available in Windows Server 2012, Powershell v3 has the following commands that might be useful to you:

Get-DnsServerZone
Get-DnsServerResourceRecord

The first will get you all the zones The second will get you the records for whatever zone you pass to it

They are basically the equivalent of DNSCMD's /EnumZones and /EnumRecords.

So... You could write something like this to get ALL of the records from ALL zones:

$Zones = @(Get-DnsServerZone)
ForEach ($Zone in $Zones) {
    Write-Host "`n$Zone.ZoneName" -ForegroundColor "Yellow"
    $Zone | Get-DnsServerResourceRecord
}

Also, I'm fairly sure that server 2012 keeps an actual zonefile for each zone now? So you should have a file copy for all your zones.

If you're working with 2008 R2, then you can use this script which I use to back up all of my zones to files:

$zones = @( `
    dnscmd /enumzones | `
    select-string -pattern "\b(?i)((?=[a-z0-9-]{1,63}\.)(xn--)?[a-z0-9]+(-[a-z0-9]+)*\.)+[a-z]{2,63}\b" | %{$_.Matches} | %{$_.Value};
);

ForEach ($domain in $zones) {
    $backup = "dnscmd . /zoneExport $domain $domain";
    Invoke-Expression $backup | Out-Null
    Write-Host "Backing up $domain" -ForegroundColor "White"
};

ForEach ($item in (gci C:\Windows\System32\dns)) {
    Write-Host "Renaming $item" -ForegroundColor "White"    
Rename-item $item.fullname ([string]$item + ".dns")
}

Write-Host "Back up complete." -ForegroundColor "Cyan"
cmd /c pause | out-null

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