What is Linux networking?

Through a set of protocols and tools, such as network interfaces, routers, Domain Name Systems (DNS) and firewalls, Linux networking provides a flexible and secure networking infrastructure that many enterprises rely on for their core business applications.

Networking is fundamental to all kinds of digital communication, enabling the exchange of data and resources over the networks that underpin transformational technologies like cloud computing, virtualization, social networking and more.

As the world’s most popular open source operating system (OS), Linux plays a key role in the way these networks, network connections and network devices are configured, managed and secured.

Linux is an open source operating system (OS) based on Unix, one of the original operating systems for computing devices, developed in the 1960s. Since its invention in 1991, Linux has grown into one of the most widely used operating systems, offering a free alternative to proprietary platforms like Microsoft Windows and Apple’s macOS. Today, Linux runs on many PCs, servers, mobile phones and a wide range of other devices.

Linux networking relies heavily on the Linux kernel, a computer program that gives a user control over a system's hardware and software to operate effectively. All Linux systems use the kernel to communicate and receive Linux commands from users. 

Networking is the method of connecting computing devices, such as PCs, mobile devices, routers or applications, so they can exchange data and share resources. Devices connected over a network, also known as networked devices, rely on a set of rules known as protocols. These protocols define how data is sent and received through physical and wireless connections.

Before the invention of computer networking, computers and compute devices had to be physically moved so they could share information and resources—an unwieldy process since they were large, heavy devices. The Department of Defense created ARPANET, the first computer network, in the late 1960s to ease information and resource sharing.

Today, computer networking underpins some of the most transformational technologies in the world, including the internet, search, social media and more.

Linux networking relies on four key concepts to function:

• Configuration

• Management

• Security

• Virtualization

Together, these concepts outline how networks can be set up, where devices can be located, and how they can share information. Here’s a closer look at each one.

Linux network configuration is the management of network-related aspects, such as network interfaces, routing and DNS, that are critical to network functionality. In a Linux networking configuration, the network interface describes how a device is connected to a Linux network (physical or virtual). Routing and routing tables refer to the path that information, also known as network traffic, can take over the network.

To enable network configuration, Linux supports various protocols—rules that govern how network traffic can be shared between devices—such as TCP/IP, DHCP, ICMP, IPv4, IPv6 and UDP. It also includes tools for troubleshooting. Command-line tools like netstat, ifconfig, traceroute and tcpdump are text-based interfaces that allow users to interact directly with the network through the OS.

Domain Name Systems (DNS) convert specific domain names (for example, web addresses) into Internet Protocol (IP) addresses, allowing devices on a network to access them. IP addressing plays a critical role in network configuration because IP addresses are often complex series of numbers that are more difficult for users to memorize than domain names.

Finally, firewalls are systems that are set up during network configuration that monitor all incoming and outgoing traffic on a network, keeping it secure.

Linux network management is a set of tools and practices for monitoring network traffic, services and connectivity. These tools and practices can range from establishing a simple network interface. They also extend to the installation and configuration of complex network infrastructures for a modern cloud environment.

Network monitoring is a key aspect of Linux network management. It involves tools for tracking network activity and identifying and resolving issues that could impact network performance. One example is netstat, a command-line Linux tool that provides information about the functionality of Linux network connections, routing and interface performance.

As capabilities and technologies have improved, Linux network management increasingly relies on automation. Today, systems automatically handle many tasks—such as configuring network interfaces, monitoring traffic and checking system states—streamlining and simplifying critical processes.

Linux networks—connected systems running the Linux OS—use various tools and technologies to protect users and systems from unauthorized intrusions. Here’s a look at some of the most effective ones.

• Firewalls: Firewalls are systems that control network traffic based on a set of predefined rules. On a Linux network, firewalls act as barriers between trusted internal networks and untrusted, external networks (like the internet). One of the most popular Linux networking tools for firewall management is iptables, a command that controls firewall rules and network traffic.

• Open-source code: Linux’s open source code is one of its strongest defenses against security threats and data breaches. A global community of experts constantly reviews and improves the code that powers Linux systems, quickly addressing any vulnerabilities.

• Access control: In Linux networking, access control refers to the practice of limiting user permissions (that is, the ability to modify files and processes on a system) through a set of rules and mechanisms.

• Encryption: On Linux networks, protocols like SSL/TLS and IPsec encrypt data in transit, preventing unauthorized users from reading or understanding it as it moves between networks.

• Logging: Logging, the practice of recording all activities relevant to network operations, helps ensure that system processes are closely monitored. These records can be reviewed when unwanted intrusions or suspicious activities occur on a Linux network.

Virtualization is a technology that allows for the sharing of multiple compute resources from a single physical machine. Linux network virtualization helps virtualize network resources that are typically hardware-dependent, such as routers and switches, so they can be allocated and used more efficiently.

To support this process, Linux networks create an abstraction layer between applications and hardware, simplifying the management of the hardware through the application. Abstraction layers are critical to making applications more portable and flexible in a virtualized environment.

Linux networks are well suited to virtualization because of their open source nature. They also use Kernel-based Virtual Machines (KVMs), a virtualization module built into the Linux kernel that enables it to function like a hypervisor.

A hypervisor is software that allows numerous instances of VMs, each with their own OS to run concurrently on one physical server. On non-Linux systems, hypervisors actively allocate various compute resources to virtual machines, while on Linux systems, KVM handles this resource allocation.

Linux networks are widely used by some of the most successful businesses in the world to connect and enable their core business applications and processes. Here are some of the most popular benefits of Linux networking.

Due to its open nature, flexibility and security features, businesses of all sizes and across a wide range of industries depend on Linux networking for their most complex networking needs. Here are some of the most popular Linux networking use cases at the enterprise level.

The Linux OS and Linux networking are widely used to host millions of business websites and data centers. These systems support core business functions such as e-commerce, software as a service (SaaS) sales and more.

Linux provides a stable and secure environment for running web and application servers that support many resource-intensive business applications. According to a report last year by Enterprise Apps, Linux powers over 96% of the top million web servers in the world.¹

Linux OS underpins most instances of cloud computing, the on-demand access to compute resources that has become the foundation of most enterprise-level IT environments. The most popular cloud platforms in the world, such as Amazon Web Services (AWS), Microsoft Azure, Google Cloud and Google Drive, all run on Linux and Linux networking.

Many advanced enterprises operating today rely on Linux networking and its robust suite of security features to protect their networks from complex cyberattacks.

Linux networks have some of the best-designed firewalls in the world, with specialized tools like iptables and nftables that are unique to Linux environments.

Linux networks are optimized for containerized applications, units of software that bundle an application’s code library and dependencies so the application can run in multiple environments. Today, containers dominate the modern application market, with a global market value of USD 5.85 billion. This value is expected to grow at a compound annual growth rate (CAGR) of 33% over the next 5 years.²

Linux networks support many modern DevOps environments that rely on containerization to ensure the code they’re shipping is fully tested in all applicable environments.