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Network Security

Network security fundamentals cover how to protect the perimeter of a network, control data flow through segmentation, and manage access to critical infrastructure resources. Segmentation is a central strategy for limiting exposure and maintaining control over traffic moving in and out of a network.

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About this video

Network security starts with understanding and protecting the perimeter, which represents the boundary of a network and all the entry points through which traffic can flow in or out. Designing a secure network means making deliberate choices about what types of connections are permitted, which devices are deployed, where those devices are positioned, and how they are configured to enforce security policies. Segmentation is a foundational technique in network security, involving the division of a network into separate zones to control how data flows between them. By creating these logical and physical separations, organizations gain greater visibility and control over internal traffic, reduce the risk of lateral movement by attackers, and limit the blast radius of a potential breach. Segmentation applies across many layers of infrastructure and is particularly effective at enforcing boundaries between sensitive and general-purpose environments. Access control is equally critical. The network itself, along with the data, servers, databases, encryption keys, and certificates it hosts, all qualify as resources that require protection. Determining who and what can access these resources — and under what conditions — is a core responsibility in any network security strategy. Together, segmentation and access control form the backbone of a well-architected, defensible network environment.

What you'll learn

What's covered

Network Security Overview

Key terms

Network Segmentation
The practice of dividing a network into smaller segments to improve performance and limit the spread of security threats.
Firewall
A network security device that monitors and controls incoming and outgoing traffic based on predefined security rules.
Access Control
A security mechanism that restricts access to resources based on policies, roles, or identity.
Demilitarized Zone
DMZ
A network segment that sits between a trusted internal network and an untrusted external network, hosting public-facing services.
Ingress Filtering
The practice of monitoring and restricting inbound network traffic based on security policies.
Egress Filtering
The practice of monitoring and restricting outbound network traffic based on security policies.
Network Perimeter
The boundary of a network that separates internal trusted resources from external untrusted networks, defined by its entry and exit points.

Topics

Network Security Network Segmentation Perimeter Security Access Control Network Architecture Data Flow Control

Transcript

The perimeter

When it comes to network security, one of the big things that we look at is the perimeter of our network. What is the perimeter? That is the outside of our network. That is the entry points which people can get into, or machines can get into, our network. So we want to look at that perimeter and set up different access into this network.

As we're architecting our network, we're going to take a look at the type of connections that we need. We're going to look at the devices that we need on that network, where to put those, and how to configure them.

Segmentation

One of the best ways that we can control what comes into the network and goes out of that network, and then also what happens within that network, is segmentation of those networks. Segmentation is one of the things that we want to do to a lot of different aspects of our data and our networks and whatever infrastructure that we're talking about. We can create these separations, but it comes especially true when we're talking about our networks. Separating our networks can really help us control how the data is flowing in and out of these networks and what's happening on them.

Access to resources

Another aspect that we really want to control is access to resources. Your infrastructure, your network, is a resource. So is the data that's on that network. And if there are any kind of databases or servers, or maybe the access keys into these servers, into these different files, the encryption keys, the certificates, we want to control access to all of these resources.

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