I'm in the process of studying for my CCNA Security and just finished the section about IDS and IPS. I knew about them before, but didn't know that they could be configured on a standard ISR through the SDM. I have a 2811 as our main router, then goes out to our ASA and then to our WAN router. If I implement IPS on my main 2811 router without the network modules or aim cards, about how much cpu usage does it us? Is it going to greatly slow down our network, or will I really even notice?
On the 2811, we have 2 point to point T1's, and does all the main routing. Will having IPS run off the same CPU slow down my network? Or would it be best to look into the AIM module, or something else?