Check if server is in which AD domain

Question

Please assist. I'm getting familiar with PowerShell but I'm struggling with this new script. I have a list of FQDN Hostnames. They can be in either 3 different domains (1 forest) or not present at all (e.g. in another forest).

I want a PowerShell script that outputs another txt file with hostname,found in

This is how far I have come but it's not doing much. Also, I'm not sure how the $_ works here as I found this piece of code as a solution for a similar use case.

Behind the # I placed some code I tried as well.

$dcs = @("xx.****.com","xx.***.com","xx.***.com")  | % {
foreach ($hostname in (Get-Content C:\Scripts\hostnames.txt)){
$check = Get-ADComputer $hostname -Server $_ #$hostname #-Filter { DNSHostname -eq $hostname $_}
if($check){
write-host "$hostname found in $_"
}
else{
write-host "$hostname not found in any domain"
}}}

user_15339544 · Answer

The problems I see on your code is the use of Write-Host which purpose is to output information to the host and it's output is not captured by default, if you want to output to a file you don't need to use it.

The other problem is the use Get-ADComputer -Identity $hostname, if a computer is not found, which will happen since you're querying different domains, this will give you errors. In this case it would be better to use -Filter or -LDAPFilter since both don't produce any error on an object not found, both return $null instead.

As for data export, I believe CSV is much more appropriate for data export instead of a text file, hence the use of Export-Csv.

$domains = (Get-ADForest).Domains

Get-Content C:\Scripts\hostnames.txt | ForEach-Object {
    $found = foreach($domain in $domains) {
        $comp = Get-ADComputer -LDAPFilter "(DNSHostname=$_)" -Server $domain
        # if this computer was found on this Domain
        if($comp) {
            # stop the loop here and return this object
            return [pscustomobject]@{
                ComputerName = $comp.Name
                Domain       = $domain
                Status       = 'Found'
            }
        }
    }
    # if a computer was found on the inner loop, return the object
    # and continue with next computer
    if($found) { return $found }

    # if no computer was found, return this object
    [pscustomobject]@{
        ComputerName = $_
        Domain       = ''
        Status       = 'Not Found'
    }
} | Export-Csv path/to/export.csv -NoTypeInformation

I realized later that since you already have FQDNs the following might be a better option, this one will target the specific Domain based on the FQDN, I'll leave it up to you to choose which one you want to try.

$ErrorActionPreference = 'Stop'

Get-Content C:\Scripts\hostnames.txt | ForEach-Object {
    $name, $domain = $_.Split('.', 2)
    $out = [ordered]@{
        ComputerName = $name
        Domain       = $domain
    }
    try {
        $null = Get-ADComputer $name -Server $domain
        $out['Status'] = 'Found'
    }
    catch {
        $out['Status'] = 'Not Found'
    }

    [pscustomobject]$out
} | Export-Csv path/to/export.csv -NoTypeInformation

Check if server is in which AD domain

1 Answers