How to limit simoutanious connections

I don't have the ability to do server configuration on my site. I found I can filter out suspicious IP ranges in web.config with:

         <ipSecurity>
            <add ipAddress="114.98.0.0" subnetMask="255.255.0.0" /> <!--China-->
          </ipsecurity>

This has taken care of a lot of the issues with hacking attempts but I'm having an issue with the same IP address opening up dozens of simultaneous connections. So far I have found no way to limit this. Any help would be appreciated.

IP addresses change unpredictably, and any web scraper or bot service has the ability to jump to a random IP on a whim.  This will not be feasible without access to your server management, and there is not really a straightforward solution even with access.  

Ask your hosting provider if they can install/enable firewall and/or brute force prevention services like cPHulk, Fail2ban, Modsecurity, or look into a 3rd Party service like Cloudflare.