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Perimeter Security

Jenna Phipps
Last Updated May 24, 2021 8:02 am

Perimeter security is the protection of a network by monitoring and filtering the traffic that passes through it. A network perimeter refers to the boundary between an organization’s network and the other networks it borders (notably the Internet). A few traditional methods of securing a network perimeter include:

  • Firewalls a firewall is one of the most important lines of defense for a network. It is configured by the organization to observe traffic as it passes across the perimeter, look for suspicious activity, and control Internet requests if need be.
  • Packet sniffing these programs monitor network traffic, IP addresses, and activity. They’re often used by Internet service providers to spy on Internet users’ activity, and are often used maliciously, but businesses can also employ them as a method of perimeter security.
  • Intrusion detection and prevention intrusion detection systems alert administrators if something suspicious comes to its attention. Intrusion prevention systems go a step further with automated response to suspicious network activity and can block requests altogether.

The perimeter, however, is quickly becoming obsolete. It is no longer so easily defined when a network consists of multiple cloud environments and servers in different locations. Users can now access a network through different devices, which creates greater security demand, and organizations have struggled to keep up. Edge computing on local servers requires security to be localized, rather than being concentrated in one giant data center, and that is challenging to implement. Some security providers have begun implementing secure access service edge (SASE) technologies to secure the edge more thoroughly.

When cloud computing came into common usage, businesses had to learn how to transfer workloads and applications to a new environment. And though cloud service providers work hard to manage sensitive data and secure their networks, attackers often slip through the cracks.

Attack methods have also become much more sophisticated, especially with more devices and Internet connections to use. Hackers can break even some of the most secure encryption techniques or gain access to a trusted company employee’s credentials through social engineering methods. It’s much harder to manage security at the perimeter of a network when that perimeter is all but gone.

A more focused approach to network security

If the perimeter no longer exists in the way it used to, organizations must compensate for that change. A few methods of shifting security away from the perimeter are:

  • Implementing machine learning for network monitoring automating the process of sifting through Internet traffic saves organizations time and resources. Intelligent systems can learn to better detect anomalies as they continue to arise.
  • Watching devices more carefully instead of focusing on a distant, faded perimeter, organizations should monitor the private devices that access their network. Authentication processes are a bare minimum. Endpoint detection and response is another solution for monitoring devices and users.
  • Focusing on people many security breaches happen because social engineering tactics fooled an employee. Thoroughly training workers to be more aware of threats will help an organization stay alert and defensive.

Zero trust: the ultimate goal

Though all of the solutions above will help businesses develop more specific security solutions, the current flaw of perimeter security is that it assumes everyone who comes through the perimeter is trustworthy. That is not the case. Hacking is extremely advanced, and occupational fraud is one of the most common methods of fraud committed against businesses meaning that those who have access to a company network cannot be trusted. Zero trust mitigates some of this risk by assuming that no one is trustworthy.

A zero trust approach to networks means following the principle of least privilege access: employees should only have access to the applications and accounts that they absolutely need to do their job. And each entry point, or level, of access should require authentication. Zero trust architectures use microsegmentation, which divides every section (application or account, for example) into “segments” that require credentials for entry. If an attacker makes it through the “perimeter” of a network, that doesn’t automatically give them access to every area and piece of data within the network. Zero trust is the best form of network security for large organizations simply because it assumes, correctly, that attackers will attempt to steal sensitive information and cost the company finances and resources.