We have got a deployment of IPS v6 with MARS which is thus far quite effective in mitigating most of the issues.
However I'm bit stuck with a scenario and require help, my question goes as below:-
1. For all the TCP based attacks, I guess the best way to defend is to issue a TCP Reset to the Router or PIX, however, oflately I guess more and more attacks (being reported) is of Port Sweep (TCP and ICMP) and that of many worms trying to get propaged using the ICMP.
So in these circumstances, what should be my mitigation strategy? Should I consider shunning? but, shunning doesnt look like practical as the number of hosts originating the attacks are numerous...
2. Once MARS/IPS combo is deployed, should the mitigation strategy always be deployed from the MARS appliance (just like once NMS / LMS is in place we encourage all the configurations to be deployed from LMS only) or should I continue to fine tune the Signatures / Release IDs on the individual IPS Appliancees?
Any help would be greatly appreciated.