Enable dynamic IP throttling in IIS.

Enable-DynamicIpThrottling.ps1

function Enable-DynamicIpThrottling($webSiteName, [bool] $enabled, [int]$maxRequests, [int]$intervalMilliseconds, [bool] $loggingOnly = $false) {
    ##https://docs.microsoft.com/en-us/iis/configuration/system.webserver/security/dynamicipsecurity/
    Add-Type -Path "$env:SystemRoot\System32\inetsrv\Microsoft.Web.Administration.dll"
    $manager = New-Object Microsoft.Web.Administration.ServerManager
    $config = $manager.GetApplicationHostConfiguration();
    $cpSecConfig = $config.GetSection("system.webServer/security/dynamicIpSecurity", $websiteName)

    $cpSecConfig.SetAttributeValue("enableLoggingOnlyMode", $loggingOnly)

    $requestRate = $cpSecConfig.ChildElements["denyByRequestRate"]
    $requestRate.SetAttributeValue("enabled", $enabled)
    $requestRate.SetAttributeValue("maxRequests", $maxRequests)
    $requestRate.SetAttributeValue("requestIntervalInMilliseconds", $intervalMilliseconds)
    
    $manager.CommitChanges()
    $manager.Dispose()
}