Set CName TTL

setCNameTTL.ps1

param(
    [Parameter(Mandatory=$false)]
    [string]$dnsServer,
    
    [Parameter(Mandatory=$false)]
    [string]$lookupZone,

    [Parameter(Mandatory=$false)]
    [string[]]$cnameRecords,

    [Parameter(Mandatory=$false)]
    [string[]]$CnameListFilePaths
)

# Load cname records from files if any are provided
foreach ($path in $CnameListFilePaths) {
    if (Test-Path $path) {
        $cnameRecords += Get-Content $path
    } else {
        Write-Warning "File not found: $path"
    }
}

$TTL = [System.TimeSpan]::FromMinutes(15)
$zeroTTL = [System.TimeSpan]::Zero

foreach ($cname in $cnameRecords) {
    try {
        $dnsRecord = Get-DnsServerResourceRecord -Name $cname -ZoneName $lookupZone -ComputerName $dnsServer -RRType "CName"
        if ($dnsRecord -and ($dnsRecord.TimeToLive -eq $zeroTTL -or $dnsRecord.TimeToLive -eq $null)) {
            Write-Output "Updating TTL for $cname..."
            $modifiedRecord = $dnsRecord.Clone()
            $modifiedRecord.TimeToLive = $TTL
            Set-DnsServerResourceRecord -OldInputObject $dnsRecord -NewInputObject $modifiedRecord -ZoneName $lookupZone -ComputerName $dnsServer
            Write-Output "TTL updated to 15 minutes for $cname."
        } else {
            Write-Output "TTL for $cname is already set or not zero."
        }
    } catch {
        Write-Error "Error processing $cname : $_"
    }
}