What Is a Network Switch?

A switch is a more advanced version of a hub to connect multiple PCs, printers, and more in a LAN.

Unlike a hub, a switch can intelligently direct data to specific devices based on MAC addresses, thereby improving network performance by minimizing unnecessary traffic. Switches have 8-48 ports (RJ-45/SFP Ports or both).

Switch is a multi-layered device; it can operate at L2 (Data Link Layer) and L3 (Network Layer) of OSI Model.

How Does a Switch Work?

• Switch is also a broadcasting device, it broadcasts the data for the first time but after that it makes a MAC address table and sends the data to the correct port.
• When data is received, a switch uses its MAC address table to check the destination address of the incoming frame.
• Then it forwards the frame(data) only to the device with the matching MAC address, instead of broadcasting it to every device connected to the network, which reduces network congestion and enhances security.

Advantages:

• Improved network efficiency: By only sending data to the correct device, switches reduce network collisions and traffic.
• Full Duplex: It can send and receive data at the same time.
• Scalability: Switches support larger networks and can manage increased data traffic more effectively.
• Security: Better than hubs because data is only sent to the intended recipient, reducing the risk of unauthorized data access.

Disadvantages:

• Cost: Switches are more expensive than hubs, especially in larger configurations.
• Complexity: More advanced switches, such as Layer 3 (which includes routing capabilities), require more knowledge to configure.
• Overkill in small networks: For simple networks with minimal devices, a switch may offer more features than necessary.

Use Case: Switches are ideal for mid-sized to large networks that require high-speed data transfer and better security, such as in office environments, data canters, or enterprise networks

Types of Switches

Based on functionality, scalability, and OSI layer operation, switches are categorized into several types:

2.1 Unmanaged Switches

An unmanaged switch is a plug-and-play device with no configuration options. It simply forwards data based on MAC addresses and is ideal for basic connectivity.

OSI Layer: Layer 2 (Data Link Layer)

Key Traits:

• Easy to use, no setup required
• Low cost and reliable
• No VLAN or traffic control support

Use Case: Home networks or small offices needing basic, fast Ethernet connectivity.

2.2 Managed Switches

A managed switch offers full control over the network and allows configuration, monitoring, and management through protocols like SNMP, CLI, or a web interface.

OSI Layer: Primarily Layer 2 (some support Layer 3)

Key Traits:

• VLAN support, traffic prioritization (QoS)
• Enhanced security features
• Monitoring and remote configuration

Use Case: Medium to large business networks requiring scalability, performance optimization, and network segmentation.

2.3 Layer 2 Switches

A Layer 2 switch operates at the Data Link Layer, using MAC addresses to forward frames. It’s the standard switch type for most LANs.

Key Traits:

• Basic switching functionality
• No IP routing
• Supports VLANs and MAC filtering

Use Case: Internal LAN setups where routing is handled by separate devices.

2.4 Layer 3 Switches

A Layer 3 switch combines switching and basic routing capabilities, operating at both the Data Link and Network Layers. It can route packets using IP addresses and supports protocols like OSPF and RIP.

Key Traits:

• High performance with routing capabilities
• Supports inter-VLAN routing
• Suitable for large enterprise networks

Use Case: Large-scale networks where high-speed routing between VLANs or subnets is needed.

2.5 PoE Switch (Power over Ethernet)

A PoE switch supplies power and data over a single Ethernet cable. It’s commonly used for powering IP cameras, VoIP phones, and wireless access points.

Key Traits:

• Eliminates the need for separate power cables
• Simplifies installation of devices in hard-to-reach places
• Available in managed and unmanaged versions

Use Case: Networks with connected devices that require both power and data, such as in smart buildings or surveillance systems.