No, you don’t.
I don’t what? Need to clear up? Or need IDS/IPS? 
You don’t need IDS/IPS.
Hi,
I have developed an IDS/IPS system for RouterOS.
It is here : http://sourceforge.net/projects/mt-fw-attack/
You need a linux machine to compile and run it.
It collects syslog messages from your’s routeros device (there are instructions on how to use it) and adds the attackers on an address list which you can use to block them.
