Is there any inbuilt function to stop POST scripts executing on asp.net web application

I can actually open a webrequest, and POST parameters, put it in a while loop and keep spamming POST requests
Is there any function that can prevent this?
Currently using :
<forms loginUrl="~/LoginPage.aspx" protection="All" timeout="5" slidingExpiration="true" cookieless="UseCookies" enableCrossAppRedirects="false"/>
...