If you survey a room full of IT pros and ask them to list all the security tools their organization uses, some will probably call out just a few, while others may list dozens. That span exists due to network security controls, which tend to fall into defined verticals that each mitigate a different risk type, and most businesses fail only when they learn they are missing that one category in their field. This is why being aware of these categories beforehand, rather than learning about them the hard way, separates a prepared security program from a reactive one.
A helpful overview of this complete picture comes from the types of network security for businesses. This solid starting point outlines the tools and practices needed to develop an effective security strategy.
Three Broad Categories Worth Knowing
The main functional categories of network security controls. Preventive controls are security measures that keep a threat from occurring in the first place, such as firewalls, access restrictions, and encryption. A detective controls to discover an existing attack (to detect signs of a breach), such as IDS and continuous monitoring solutions. Corrective controls respond after the incident has already happened, restoring systems and closing the doors that allowed the breach to occur.
Investing in only one of these categories typically leads to major gaps, and the most common is in preventive controls. If an attacker has found a way to circumvent an effective firewall, there will be no notification that this is happening, and no amount of prevention can remove all risk. Security ingredients, as a whole, do not focus solely on keeping attacks out of the front door; they allocate roughly equal weight across all three categories.
Access Control and Identity Management
Limiting who can access what resource is one of the oldest areas of practice in network security. This includes multi-factor authentication, which prevents unauthorized access with several layers of security beyond a password alone; role-based permissions that ensure users have only what they need to do their jobs; and regular reviews of who still needs access to a specific system. Weak access control is always among the top attack paths attackers use to get into a network, but a single credential with too much permission — even just one! —can cause far more damage than multiple credentials with fine-grained or careful scoping/rights management.
Firewalls and Network Segmentation
A firewall is a network security device that monitors and controls incoming and outgoing traffic based on predetermined security rules, allowing or blocking traffic accordingly. Segmentation advances this concept by breaking a network into discrete organizations, such that the compromise of one does not grant license to everything else. Both of these controls are arguably the most essential components of any network security program; they work together, and almost every company benefits from having both rather than relying on just one.
Encryption and Data Protection
Data protection, in itself, is a third, separate category: protecting data, not the network it moves over. That is why data should be encrypted in transit and at rest: even if someone manages to capture or access it, they would not be able to read it without the corresponding decryption key. Data loss prevention tools go a step further, monitoring sensitive information leaving the network in ways that violate policy (for example, via email or file transfer).
Formal Frameworks Behind These Categories
These categories are not arbitrary. Federal guidance on the topic: the federal catalog of security controls organizes hundreds of individual security and privacy controls into organized families that cover access control, incident response, system integrity, and dozens of other functional areas, providing organizations with a detailed guided source from which to build out their own program so they can stop guessing on what goes where.
Other, smaller organizations with limited resources are more likely to find straightforward self-assessment tools that are easier for non-experts. A structured approach specifically developed for this exact scenario, the self-assessment tool for cyber resilience offers smaller businesses a practical resource that allows them to position where their existing controls stack up and which categories are in greatest need of improvement, with specific details far deeper than what is technically needed to comply with any federal control catalog.
Monitoring and Incident Response
This is why you also need monitoring and incident response; even the best preventive controls eventually encounter something they are not designed to stop. Continuous monitoring tools can detect unusual activity in real time, and a documented incident response plan ensures the organization knows exactly what to do as soon as something is detected, rather than improvising on the fly. This is where many look in the category. Still, it can be more than a common incident, becoming an uncontrollable beast because nobody has clearly defined what to do in the first hour after discovery.
Employee Awareness as a Security Control Category
Technology cannot mitigate all risks, as many security incidents start from mistakes and faults made by people rather than technical systems. The ongoing training to recognize phishing attempts, properly handle sensitive data, and maintain basic security hygiene falls into its own category of control and is underinvested relative to the risk it actually mitigates. A manual eye for detail catches threats that automated tools overlook due to configuration complexity.
Building a Complete Program
So even top-notch controls will not mitigate all the risks your organization faces. Sorting organizations into one of these five categories ultimately reveals where they fall short about their security postures, if at all: those that map existing controls against the top-level domains in Security Scorecard’s risk assessment method and address gaps based on known risks rather than assumptions are generally considered the ones with the strongest overall posture. Such a structured approach can change the nature of network security from a loosely-aided set of tools into a coordinated program based on the belief that every layer will miss something. That monitoring at all levels is needed to catch it.
Frequently Asked Questions
What Should a Small Business Focus on First for Network Security Controls?
The answer is not simple, but the truth is that access control and baseline firewall protection services provide your organization with the greatest risk reduction as it begins to formalize its security program.
Do these categories of controls differ from industry to industry?
The categories themselves are generally consistent, but the actual controls within each category vary based on specific industry regulations and the data sensitivity an organization handles.
If a business has decent network security controls, how often should they be reviewed?
However, it is good practice for organizations to re-evaluate their controls at least once per year, although larger changes (e.g., new software, new locations, or changes in business processes, such as moving from on-site to remote work) usually call for review sooner than the yearly milestone.
