COMPUTER NETWORK SWITCH

A computer network switch is a device that connects multiple devices within a network, forwarding data only to the intended recipient rather than broadcasting to all devices. Switches use MAC addresses to identify devices and direct traffic with precision making networks faster, more secure and more efficient.

There are several types of computer or network switches and they are; unmanaged , smart, managed, layer 2 switch, layer 3 switch, multilayer, PoE switch (power over Ethernet), stackable, modular, data center and virtual switches.

Unmanaged switches are simple plug and play switches with no configuration needed. Example includes; TP-Link TL-SF1008D, Netgear GS308 etc.

Smart or web managed switch is a middle ground switch with basic VLAN and QoS support via a web browser. Example includes; Netgear GS308E, TP-Link TL-SG108E, Cisco SG250 etc.

Managed switch have full control over every aspect of traffic, security and monitoring. They have full VLAN, QoS, ACL, STP support. Example includes; Cisco catalyst 9200, juniper EX series, HP Aruba 2930etc.

Layer 2 switch operates at the OSI data link layer, forwarding packets based on MAC addresses. They support VLANs and STPs. Example includes; Cisco catalyst 2960-X, D-Link DGS-1210 etc.

Layer 3 switch (multilayer) combines switching and routing. It handles inter VLAN routing without a router. Example includes; Cisco catalyst 3850, HP Aruba 3810, juniper EX 4300 etc.

PoE (power over Ethernet) switch deliver both power and data over a single Ethernet cable. Therefore it can power devices without wall outlets. Example includes; cisco SG350-28P, Netgear GS308PP, ubiquiti UniFi POE etc.

Stackable switch are multiple physical switches connected to act as one logical unit. Example includes; cisco catalyst 9300, Dell EMC N-series, juniper EX2300 etc.

Modular switch are chassis based with interchangeable line cards. They are built for maximum flexibility and uptime. Example includes cisco catalyst 6500, juniper EX9200, Aruba 8400 etc.

Data center switch are optimized for ultra-high throughput and ultra-low latency in cloud environments. Example includes; cisco Nexus 9000, Arista 7050X, juniper QFX5120 etc.

Virtual switch are software based switch running inside a hypervisor to connect virtual machines. Example includes; VMware VDS, openVswitch (OVS), Microsoft Hyper-V virtual switch etc.

The advantages of computer or network switches are; their use enhances the performance and efficiency of the network since they forward data only to the intended device eliminating unnecessary traffic and reducing network congestion. Switches allows for full duplex communication by allowing simultaneous sending and receiving on every port. Hardware based on switching operates at wire speed with very low latency. The network is easily expanded by adding more switches or using modular and stackable designs that allows growth without redesigning the network. Managed switches offer remote diagnostics and fault detection. Traffic isolation between ports reduces risks of eavesdropping and port mirroring enables traffic monitoring and intrusion detection. Switches are generally reliable, cost effective and have a long life span especially the modular chassis designs.

The disadvantages of computer or network switches are; high end managed modular and data center switches are very expensive. Skilled networks engineers are needed because of their complexity thereby increasing operational cost. They require proper VLAN design to contain broadcasts effectively. They are vulnerable to MAC flooding attacks, ARP spoofing and VLAN hopping if not hardened. Unmanaged switches have zero built in security and physical access to a switch port can expose the entire network segment. A core switch failure can bring down an entire network segment and they require redundant switch pairs and uplinks to eliminate single point of failure adding cost to the network.

Computer or network switches find applications in the following; enterprise and corporate networks to connect thousands of work stations, servers, printers and phones across offices and campuses. Data centers and cloud, where they form the backbone of server connectivity. Health care to segment medical device traffic, support IP nurse call systems, power IP cameras and ensure network uptime for patient critical systems. Industrial and manufacturing, switches are used to connect PLCs, SCADA systems, sensors and robotic equipment. They are also used extensively in retail, hospitality, and telecommunication, smart buildings to connect numerous devices and equipment together.

The future of computer or network switches are based on the advances and development of the following technologies; software defined networks, AI and machine learning, internet based networking (IBN), 400G, 800G and beyond network technologies that will be driven by AI training clusters, Video streaming and big data, switch port speeds will continue climbing. Silicon photonics and co-packaged optics will deliver this bandwidth at lower power and smaller form factors.

 

SOURCES:

• Computer networks by Andrew S. Tanenbaum.
• Networking all in one for dummies by Doug Lowe.
• Computer networking: A top down approach by Kurose and Ross.
• Network warrior by Gary A Donahue.
• Cisco networking all in one for dummies by Edward Tetz.