What's IDP & ISP

Posted by shentanli on March 05, 2020 ·


Mention network, the firewall comes first. A firewall does the filtering, blocking and allowing of addresses, ports, service, but also allows some of these through the network as well. However this means that the access allowed is just let through, and firewalls have no clever way of telling whether that traffic is legit and normal. This is where the IDS and IPS systems come into play.
Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) are both parts of the network infrastructure. IDS/IPS detect and look at that traffic in close detail to see if it is an attack. IDS/IPS systems are made up of sensors, analysers and GUI’s in order to do their specialised job. The main difference between them is that IDS is a monitoring system, while IPS is a control system. IDS analyzes network traffic for signatures that match known cyberattacks, Besides, IPS also analyzes packets, but can also stop the packet from being delivered based on what kind of attacks it detects — helping stop the attack.


The three IDS detection methodologies are typically used to detect incidents:

  • Signature-Based Detection compares signatures against observed events to identify possible incidents. This is the simplest detection method because it compares only the current unit of activity (such as a packet or a log entry, to a list of signatures) using string comparison operations.
  • Anomaly-Based Detection compares definitions of what is considered normal activity with observed events in order to identify significant deviations. This detection method can be very effective at spotting previously unknown threats.
  • Stateful Protocol Analysis compares predetermined profiles of generally accepted definitions for benign protocol activity for each protocol state against observed events in order to identify deviations.


IPS have the ability to take actions on defined policies such as blocking a connection, providing alerts, logging the event, quarantining the host or a combination of these. Policies define the rules that specify what should be detected and type of response required. Policies will include both signature based rules and anomaly detection rules for learning typical network traffic and setting thresholds for these. DOS and reconnaissance rules are based on traffic statistics. IPS solutions also provide logging and alerting on recent attacks so it should be easy to understand and trace an attack, and provide supporting tools that would aid in blocking attacks. Also clicking the attack should provide detailed information about the attack and what can be done to resolve such an attack.


  1. Varonis.
  2. Ics.
  3. Juniper.