All You Need to Know About Intrusion Detection Systems - Direc Business Technologies, Philippines

All You Need to Know About Intrusion Detection Systems

What is an intrusion detection system?

  1. Detects suspicious activity
  2. Sends alerts to IT personnel
  3. Types of Intrusion Detection Systems
    1. NIDS
    2. HIDS
    3. APIDS
    4. HIDS

If you find yourself asking the question of what is an intrusion detection system, then it’s more than likely that you want to find ways of protecting your business from cybersecurity attacks. As technology continually gets more innovative, so are cybercriminals who are hoping to take advantage of vulnerabilities in networks, computers, and other systems. Without an awareness of how they operate, your business might run the risk of exposing itself to these ever-pervasive cybersecurity threats.

Hackers typically employ a number of tools that allow them to intercept these systems. Businesses who are too lax with their security protocols might end up experiencing cybersecurity problems that may have far-reaching problems for the entire company. Fortunately, there is a way for you to stop these threats from fully taking place and subsequently coming up with solutions to eliminate them. Continue reading to learn more.

Detects suspicious activity

Workers At An It Company Working On A Computer

The single most important thing that intrusion detection systems do is detect suspicious activity that occurs in a network. This may be activity that contains signatures or patterns that the system doesn’t recognize from before. As such, the detected activity can be a cause for action. Attacks can target network traffic, software, and other applications that may be utilizing network activity on a given computer or mobile device.

Based on the name alone, the main job of an IDS is to primarily monitor, or “listen” to traffic and identify elements and patterns which seem out of place. These systems are not to be confused with intrusion prevention systems that are able to identify potential attacks simply from monitoring network packets. The primary goal is for the prevention of threats, as opposed to merely detection and recording — as done by an IDS.

Sends alert to IT personnel

One thing that you should know about IDS, is that they should be used alongside other cybersecurity suites. Knowing from their function alone, it’s best if they’re integrated with other programs and software that are designed to eliminate cyberattacks.

Once an IDS is able to monitor firewalls, management servers, files, and other patterns, they send alerts to IT personnel or people who are responsible for dealing with these threats in a business. The alert typically contains information, like the intrusion’s source address, the target, as well as the kind of attack.

With this information, a company’s security team could trace the attack back to the proper source and make the necessary actions based on that. The presence of the alert means the attack could be prevented from doing further damage than the initial infiltration. On the other hand, the alert could also be directly collected by a security information and event management system (SIEM) which simply filters out truly malicious attacks, from false positives.

Types of intrusion detection systems

Business Person Logging In To His Laptop

As mentioned before, an IDS can be a software or an application that is able to scan a network or an entire system for sources of potential breaches. There are many different types of IDS, depending on the scope of the software. This can be classified into a network IDS, host, IDS, application protocol-based IDS, and a hybrid IDS.



The network intrusion detection system or NIDS arguably covers the widest scope out of all the other types. They’re situated in strategic locations throughout the network, where they’re able to monitor all incoming traffic that takes place. In the past, there may have been concerns about an NDIS being able to interfere with the network, but they only primarily perform read-only functions.

Like many systems, NIDS can either be hardware or software-based. It’s best if you identify your business’ requirements before making a choice on which of the two to implement for your organization.


A host-based IDS covers smaller, more specific areas of detection. Instead of monitoring singular network traffic, host-based IDS are installed in individual computers and systems. The information that is collected are those which are found in devices like computers or laptops that are connected to an organization’s main network.

An HDIS is considerably more detailed because it’s also able to identify which applications or users are unknowingly harboring malicious activity. Another advantage an HDIS has over an NDIS is that they’re able to provide information on the end-result of an attack.


An application protocol-based IDS should not be confused with a protocol-based IDS. The latter is usually placed at the front end, as opposed to the server. They’re consistently monitoring the flow of information exchange and protocols (usually within the HTTPS protocol stream) that take place between the user and the device they’re using and the server.

On the other hand, an APIDS is located in a server group. They are able to monitor and interpret protocol signatures like TCP/IP, HTTP, FTP, or UDP/IP.

Hybrid IDS

Simply put, a hybrid IDS is a combination of two or more types of intrusion detection systems. Organizations may have a wide variety of network requirements and they may require a more comprehensive approach to cybersecurity protection.

Key Takeaway

In simple words, intrusion detection systems are applications or software that are designed to identify patterns and signatures in a given network traffic, or across multiple devices. Patterns that seem to deviate from previously-recognized ones are then sent to a security management system, or directly to IT personnel. The source of the potential attack can then be addressed even before they can do more damage.

Want to find out if an IDS is right for your business? Direc Business can help you out. Click here to get in touch!