Get Sites and Subnets in AD Forest

The script below was written so the networking staff would be able to always have a current list of the AD Sites and Subnets, without relying on the Active Directory Module.

<#
Get-ADSubnets.ps1
Alan Kaplan 1/24/20
Get list of AD Subnets in Forest
Does not rely on AD module or admin rights
#>

#Default logfile
$desktop = [environment]::GetFolderPath('Desktop')
$logfile = "$Desktop\SitesAndSubnets_" + $(Get-Date).ToString("yyyyMMdd_HHmm") + '.csv'

$Forest = [System.DirectoryServices.ActiveDirectory.Forest]::GetCurrentForest()
Write-Host "Getting All Sites and Subnets in $forest, please wait ...."
@(
    $forest.Sites |
    Where-Object { $_.domains.count -eq 1 } |
    Foreach-Object {
        Write-Progress $_.Name
        [PScustomObject]@{
            Domain   = $_.Domains[0]
            Site     = $_.name
            Subnets  = $_.Subnets -join "; "
            DCs      = $_.Servers -join "; "
            Location = $_.location -replace '\,',','
        }
    }) | 
Sort-Object Domain, Site |
Export-csv $logfile -NoTypeInformation

Write-Progress "Done" -completed
Clear-Host
Write-host "Done. Report is $logfile"
#Open report when done
#invoke-item $logfile

Line 16 filters out the irrelevant forest root entries.  Line 24 is a simple LDAP escape for when there is a comma in the location field.