What are IDS and IPS? Also, what do they have to do with firewalls?
An Intrusion Detection System (IDS) monitors for harmful traffic and alerts you when it enters your network. This is much like a burglar alarm. An Intrusion Prevention System (IPS) goes farther and prevents the harmful traffic from entering your network. IDS/IPS systems recognize more that just Layer 3 or Layer 4 traffic. They fully understand how hackers use traffic to exploit networks and detect or prevent that harmful traffic on your network. Today, many IDS/IPS systems are integrated with firewalls and routers.
