IT Guide: Understanding Perimeter Security

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What Is Perimeter Security?

In the IT realm, perimeter security involves safeguarding a company’s network limits from hackers, intruders, and other unwanted individuals. It includes surveillance detection, analyzing patterns, recognizing threats, and dealing with them effectively.

Every private network has a perimeter around it. It’s the secure boundary between networks, for instance, your company’s private intranet and the ‘public’ internet.
Your Managed Service Provider (MSP) or at times the internal IT department, deploys systems that keep your network secure from outside threats from the public web. These threats include hacking attempts, malware, ransomware, and others trying to infiltrate the network.

There are a few components of a network perimeter including firewalls, border routers, Intrusion Detection Systems (IDS), Intrusion Prevention Systems (IPS), and Unified Threat Management (UTM) systems.

Border Routers

Routers direct traffic into and out of networks – border routers are the last on the company’s private network before traffic goes on to public networks on the internet.

Firewalls

A firewall is a device with a filtering mechanism, containing a predefined set of rules to allow and restrict traffic from the public to enter the private network and vice versa. It’s an additional safety mechanism to protect a company’s network from unwanted packets of information that may be hiding threats.

Intrusion Detection Systems – IDS

Intrusion detection systems monitor the traffic and information ‘packets’ being transferred between public and private networks.

It tallies all information against a known list of cyber-attack signatures, and your Managed Service Provider (MSP) takes necessary action to stop harmful information from entering your company’s private network.

They can compare network activity with the prebuilt threat database that can detect different security violations, port scanners, and malware.

The IDS is basically an alarm system that alerts the company about suspicious activity. It’s built from a single device or can use strategically placed sensors on different points of a network.

Intrusion Prevention Systems – IPS

Intrusion prevention systems are control systems that can accept or reject data packets based on a preset list of rules that are updated regularly by your managed service provider or automatically.

In comparison to a traditional IDS system that notifies administrators and your MSPs about threats, Intrusion prevention systems can have an automated defense mechanism to stop the information from entering the network without human intervention.

Unified Threat Management (UTM) Systems

Unified Threat Management (UTM) systems protect the network by combining features of IDS and IPS systems.

A single security device provides many security functions from one point in the private network. Thanks to the antivirus, firewall, anti-spyware, anti-spam, virtual private network (VPN) and other functions, the information entering a company’s network stays protected.

A UTM system protects against viruses, hacking attempts, malware, malicious attachments, and more thanks to deep packet inspection.

Deep packet inspection (DPI) does a complete evaluation, inside and out, of the data being transmitted over the network and performs checks for compliance violations such as spam, Trojans, viruses, or other defined criteria. If it notices these violations, it blocks the information from being received or transmitted.

Defining The Perimeter

Your managed service provider (MSP) or IT department has to know the complete layout of your network perimeter and understand it to provide the best possible security.

Continuous scanning and assessment of this perimeter can help you identify when company resources and data are misused by individuals or are under threat by hackers.

However, it has become dynamic due to the possibilities of working remotely and using your own devices (BYOD), but that doesn’t negate the fact that entry and exit points for a private network such as that of a business must be protected.

Monitor Passively

Passive monitoring tools can be useful in discovering devices that are connected to the network to see how much access and discretion they’ve been granted. These tools scan the network for weaknesses and vulnerabilities, locating the different devices connected to the network.

These devices may be remote servers, routers, desktops, security devices, application routers as well as firewalls. The monitoring tool can analyze the configuration, operating system, installed apps, and patch levels of these devices to find vulnerabilities that allow hackers unauthorized access.

The passive tools need to be activated or scheduled manually by your MSP or IT department to perform vulnerability checks.

Monitor Actively

Active monitoring tools allow for continuous surveillance of your network, scanning it for irregular traffic patterns, unknown IP structures, communications, and transmission of data. These tools can help your MSP map out architecture for your business’s private network and help set guidelines for communication between devices on the network. This helps your employees stay compliant with company guidelines.

These tools monitor your most critical business assets and apps, taking action against illegal access, employee misuse of resources, malicious content, and other security fallouts. They audit your security in real-time, creating logs and reports to meet security compliance policy requirements.

Network Zoning

The concept of zoning takes all the areas of a network into account and divides them into controlled, uncontrolled, restricted, and secure zones.

The main advantage of zoning comes from restricting a potential security breach to individual zones where it occurred, preventing it from entering other zones.
Network boundaries help separate networking zones with different security policies. These boundaries create restrictions on the kind of traffic that’s permitted in different zones. For instance, HTTP traffic may be restricted on specific ports or restricting HTTPs traffic coming from other ports from the public networks (internet and other uncontrolled networks).

Firewalls can be used to allow and restrict traffic – the firewall sends back the information packet or traffic where it came from, by readdressing - the traffic being sent back looks like it came from an address connected to the firewall. In this way, the identity of the trusted network stays hidden from the other untrusted networks connected to the internet.

Key Takeaway

Perimeter security is a philosophy that involves setting up functional devices, tools, and techniques around the boundary of a network to secure its data and resources. It is one facet of the greater security field and plays a vital role in active system protection.

So essentially, perimeter security experts take a perimeter-based approach to secure your systems and ward off any threats before they enter the network. They follow best practices like threat recognition, pattern analysis, and surveillance detection to set up high-quality and highly efficient processes to ensure internal security.

If you would like to know more about perimeter security or have any questions or concerns that need answering, please don’t hesitate to get in touch, or browse our library of free IT Guides.

TUCU is a Managed Services Provider in Toronto, offering IT security, support and management. We use perimeter security as well as zero trust security frameworks to help our small and medium business clients secure and protect their organizations.

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