Which security technology is used to passively monitor network traffic with the objective of detecting a possible attack?

Which security technology is used to passively monitor network traffic with the objective of detecting a possible attack?

• IPS
• IDS
• proxy server
• firewall
  

  Answers Explanation & Hints: An IDS system is implemented to passively monitor the traffic on a network. Both an IPS and a firewall actively monitor network traffic and take immediate actions when previously defined security criteria match. A proxy server, when it functions as a firewall, also actively monitors the traffic that travels through it and takes immediate actions.