sit on the network and monitor traffic searching for signs of potential malicious activity like  -intrusion detection -malformed packets attempting to create a denial of service -botnet -unusual logins
sit on the network and monitor traffic searching for signs of potential malicious activity like  -intrusion detection -malformed packets attempting to create a denial of service -botnet -unusual logins
a system that creates logs of all network traffic that was permitted to pass the firewall and then analyzes those logs for signs of attempted or successful intrusions