This software can scan limit of connections from one IP adress to your server, also ConnectServer of BOR tm. i think work same.
It's help only from not big syn flood, against DDoS attacks can help only VPN filtering like with CISKO routers and other serious methods.
I think, for buying serious router for your server foolishly, many hostings start work with Anti-DDoS systems, if you need good protect for your server you can use hostings like DDoS Guard - attested with me.
Screen of this software: