Network security creates shielded, monitored, and secure communications between users and assets. Despite the rapid evolution of what constitutes the users, assets, and connections, the fundamentals of networking security remain the same: block external threats, protect internal network communications, monitor the network for internal and external threats, and ensure that users only access authorized parts of the network.
Securing the expanding, sprawling, and sometimes conflicting collection of technologies that make up network security provides constant challenges for security professionals. We will examine these fundamentals as well as the shifting nature of networking security through the following sections:
Network Security Defined
To understand the shifting requirements and technologies, we must examine the contrast between earlier simple networks and newer, complex networks.
Older Simple Networks
The original simple networks connected individual users and their computers (originally terminals) to a router or switch. The router or switch then facilitated communication between the other devices on the network such as other servers, network storage, and printers. When the internet arrived, the network added a firewall to protect networks and users as they connected to the world wide web.