Get-ADUser using old pre-Windows 2000 Logon name instead of CN - powershell

Question

I'm trying to use Add-ADGroupMember cmdlet in PowerShell, but I've realized PS doesn't recognize the object if I use the CN, and it only seems to recognize the pre-Windows 2000 logon name.
That attribute had a character limitation of 20 characters, so some of our accounts have different CNs and Pre-Windows 2000 logon names.
My whole process is:
Step 1: Get a list of my users (this gives me the legacy pre-Windows 2000 logon names):
Get-ADUser -Filter {department –notlike “Field”} –SearchBase “OU=Accounts,OU=HQ,OU=Production,DC=MYDC,DC=MYDC1,DC=MYDC2” -Properties department | select name | Out-file C:\Users\Public\Users.txt
Step 2: Add those users to my security group:
$UserList = Get-Content "C:\Users\Public\Users.txt"
$GroupName = "MY-SEC-Group"
$Members = Get-ADGroupMember -Identity $GroupName -Recursive | Select -ExpandProperty SAMAccountName
ForEach ($user in $UserList)
{
If ($Members -contains $user)
{
Write-Host "$user is member of $GroupName"
}
Else
{
Write-Host "$user is not a member. Attempting to add now, run script again for verification"
Add-ADGroupMember -Identity $GroupName -Members $User
}
}
For all accounts where the legacy logon name and the CN are the exact same, there are no issues. But in situations where they are different, I get the error "Object not found"
Is there a better/more up-to-date cmdlet to use? Maybe one that relies on the CN instead of the legacy logon name? Or do I need to add in CN to all my scripts now?

Answer 1

Get-ADGroupMember returns objects that point to the concrete user in ActiveDirectory and contain different fields including distinguishedName, SamAccountName , SID, Name and so on. In your code you create a txt file with Names (not SamAccountName) but use SamAccountName in Get-ADGroupMember. So, you just compare names with SamAccountName values (that's incorrect).
Just replace
select name | Out-file C:\Users\Public\Users.txt
with
select SamAccountName | Out-file C:\Users\Public\Users.txt
SamAccountName (just as SID) is the unique attribute in AD -
https://blogs.technet.microsoft.com/389thoughts/2017/02/03/uniqueness-requirements-for-attributes-and-objects-in-active-directory/ so, you should use it in your code.