Ruth Victor

A network switch facilitates communication among users, applications, and equipment within a network, enabling resource sharing. Basic switches connect devices within a single local-area network (LAN), while advanced switches extend connectivity across multiple LANs and may include basic security features.

Advanced switches, though capable of more than simple LAN interconnection, primarily serve to connect devices in IT networks. They can create virtual networks, allowing network administrators to isolate groups of systems for security purposes. Virtual network types like virtual private networks (VPNs), virtual LANs (VLANs), and Ethernet VPN-virtual eXtensible LANs (EVPN-VXLANs) are commonly used in midsize and large networks, with EVPN-VXLAN becoming increasingly prevalent in modern enterprise setups.

Network switches vary in speed, capabilities, and sizes, supporting anywhere from a few to thousands of devices. Multiple switches can be interconnected, forming different network topologies. A modern "spine-leaf" topology, for example, utilizes high-speed switches with high port density to connect tens of thousands of devices in a single network. In spine-leaf data center networks, leaf switches aggregate traffic from servers and connect to spine switches, which interconnect all leaf switches. Such networks often employ EVPN-VXLAN for segmentation, making them suitable for multitenant data centers, government, and large enterprise use.

A network switch facilitates inter-device communication by adhering to standard communication protocols established and maintained by international standards organizations like the IEEE and the IETF. Devices connect to a network using radio (Wi-Fi), electrical (RJ-45 Ethernet), or light-based optics (fiber-optic cabling). Each connection method employs a distinct physical interconnection—RF spectrum, copper cabling, or fiber-optic cabling—over which devices communicate by exchanging streams of 1s and 0s. Network standards ensure these streams are interpreted into packets, consisting of headers and payloads. Packet headers contain source and destination addresses, while payloads carry the exchanged data. Each device on a network has one or more addresses to which packets can be directed. Packets exchanged between addresses form "data flows," akin to conversations among networked devices. Switches read addresses from packet headers and forward packets toward their destinations based on lookup tables (LUTs). LUTs maintain lists of addresses reachable via specific switch ports. Additionally, routers can be configured with "routes," directing switches to send packets with certain destinations to intermediary devices. For instance, a smartphone accessing a web page via a home Wi-Fi network connects to an access point (AP), which contains a built-in RJ-45/Ethernet switch linked to an Internet router.

Devices such as smartphones access web servers and other remote resources through a series of interconnected switches and routers communicating with each other, hop by hop, from source to destination and back. This communication occurs using standard communications protocols and addressing schemes.

As a packet of data leaves the smartphone's radio, it's received by the access point (AP). Upon inspection, if the AP doesn't recognize the destination address in the packet header, it forwards a copy of the packet to the Internet router as per its configuration. The data packet then embarks on its journey across the Internet, traversing routers and an unknown number of switches in between until it reaches the web server. Upon receiving the packet, the web server responds by sending data packets back along the same path, eventually reaching the original source Internet router, the AP-embedded switch, and finally, the smartphone. This packet exchange establishes a data flow between the smartphone and the web server, facilitated by numerous hardware devices and associated software. Throughout this process, adherence to long-standing standards ensures seamless communication between the source and destination.

Understanding the varieties of network switches is essential for finding the suitable solution to adapt to your evolving business needs. Consider different switch categories and their specific advantages as you explore available options.

Types of Switches

Modular switches

Modular switches offer the flexibility to add expansion modules as required, accommodating changes in network requirements. These modules, tailored to specific applications, encompass functionalities such as firewalls, wireless connectivity, or network analysis. They may also support additional interfaces, power supplies, or cooling fans. While providing maximum flexibility, this type of switch typically comes at a higher cost.

Fixed-configuration switches

Fixed-configuration switches come with a predetermined number of ports and usually cannot be expanded, resulting in a lower overall cost. This category encompasses unmanaged switches, smart switches, and managed switches.

Unmanaged switches

Unmanaged switches are primarily utilized for fundamental connectivity purposes. They are designed to be plug-and-play, requiring no configuration. Unmanaged switches are best suited for scenarios where basic switching and connectivity suffice, such as in home networks or in environments requiring only a few ports, like desks, labs, or conference rooms. While some unmanaged switches may offer limited advanced features, their core characteristic is their inability to be modified or managed, as implied by their name.

Smart switches

Smart switches provide partial management functionalities, including segmentation, quality of service, and security features, making them a cost-effective option compared to modular switches. However, they are not as scalable as managed switches. Smart switches are commonly deployed at the network edge in large networks, as infrastructure for smaller networks, or in networks with low complexity, while managed switches are typically used in the core.

Managed switches

Of all fixed-configuration switches, managed switches are engineered to offer the most extensive array of features, ensuring optimal application experience, top-notch security, precise network control and management, and maximum scalability. Consequently, managed switches are typically employed as aggregation/access switches in expansive networks or as core switches in smaller networks. As the priciest option among fixed-configuration switches, managed switches are prevalent in organizations with sizable or expanding networks.