What Is a Gigabit Switch?
A gigabit switch is a type of network switch, typically Ethernet-based, that allows devices to be connected to a LAN at speeds of 1 Gbps or higher. Gigabit Ethernet replaced Fast Ethernet as the current network standard.
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Why are Gigabit Ethernet switches important?
Gigabit Ethernet switches are the foundation to most LANs today. Introduced in 1998 as part of the IEEE 802.3z Gigabit Ethernet standard, gigabit switches were first used as core switches in larger 3-tier LANs. Since then, as more devices connect to more apps, and download more bandwidth-intensive content like video, the network connecting them has had to provide more bandwidth from edge to core.
Access layer switches that had typically provided Fast Ethernet speeds (10–100 Mbps) to end devices or Wi-Fi access points now support 1 Gbps and above. This requires speeds in the distribution layer and core switches to also increase, from 1G/10G to 25G/50G at the distribution layer, and from 10G/40G to 50G/100G and beyond at the core.
What is Ethernet?
Ethernet is the digital communications protocol that is the basis of nearly all shared networks, including the internet, by providing a set of rules that govern how data can be packaged and transmitted between multiple users without collision.
Ethernet is based on standards maintained by the IEEE and uses the Carrier Sense Multiple Access/Collision Detection (CSMA/CD) protocol to define when to transmit, and what is to happen if a collision is detected, as well as endpoint addressing, transmission speeds, and media.
How is a switch different from a router?
A switch connects users within a LAN using MAC addresses, while a router is used to connect LANs to other area networks or to the internet. A router uses IP addresses to route transmissions.
How fast are gigabit switches?
Current Gigabit Ethernet standards define rated speeds from 1G to 800G per port, supporting everything from homes and small businesses to large enterprises and data centers. As with many other aspects of networking, speed capabilities of gigabit switches are continuously improving as networks carry greater amounts of data at higher speeds.
Does Wi-Fi 6 require gigabit switches?
No, but to take full advantage of the higher speeds Wi-Fi 6 offers, gigabit switches rated at 2.5 Gbps or higher are needed.
Do gigabit switches require new cabling?
If the gigabit switch supports the IEEE 802.3bz Multigigabit standard, Cat5e and Cat6 cabling can be used for speeds up to 5 Gbps and wirelength up to 100 meters. Speeds above 5 Gbps may require special cabling depending on cable distance. Cat6 cabling supports 10G up to 55 meters, and Cat6a and above support 10G at 100 meters with IEEE 802.3an. Fiber optics cabling is currently required for speeds above 10G.
How does a gigabit switch work?
Gigabit Ethernet switches and Ethernet switches in general connect multiple devices together by physically cabling those devices to the same switch or a network of interconnected switches (LAN). These cables include coaxial, fiber, and the Ethernet cable twisted pair. Every Ethernet-compatible device has a hard-coded physical address called a MAC address that the connecting switch uses to uniquely identify a device.
Once a device is connected to a port, the Ethernet switch manages the flow of data between the device and other devices, applications, data, cloud services, and the internet. The switching process directs incoming and outgoing data to the correct port on the switch based on the port of the sending device and the sending and destination MAC addresses. The MAC address of both sender and destination are included with the data being sent in an Ethernet frame.
When a switch receives an Ethernet packet, it stores the sending device’s MAC address and the port it is connected to in a locally held table call a MAC address table. The switch process then checks the MAC address table to see if the destination MAC address is connected to the same switch. If it is, the switch forwards the packet to the known destination port. If not, the switch broadcasts the packet to all ports and waits for a response.
If the switch is connected directly to the destination device, the device accepts the data packet, responds, and the transmission is complete. If the device is connected to another switch, the next switch will repeat the lookup and forward process until the frame reaches the intended destination.
How many ports can a gigabit switch have?
The basic switches may have as few as two ports, while a large modular system used across an enterprise setting might have multiple switches with hundreds of ports each.
Types of gigabit switches
In addition to the differentiators of speed rating and number of ports, there are several other gigabit switch types to consider.
Fixed-configuration versus modular switches
A fixed-configuration switch has a set number of ports and is not expandable, while a modular switch is designed to be scalable by physically combining multiple switch modules that then act as one switch.
A modular switch may also allow additional types of modules, such as those supporting security, wireless connectivity, or network analysis. Modules may also be added to support specific applications, or to use additional interfaces, power supplies, or cooling fans.
Smart switches
Smart switches offer management and segmentation and security capabilities to fixed-configuration switches.
While they are not as scalable as other switches, smart switches are a lower-cost alternative for certain situations. For example, smart switches can be used at the edge of large networks (with managed switches in the core), or as infrastructure for smaller, less-complex networks without scalability requirements.
Unmanaged versus managed switches
Designed to be plug and play with no configuration needed, unmanaged switches provide basic connectivity for a small LAN or single user.
Managed switches deliver more features to support the user experience, security, manageability, and scalability. Managed switches are often deployed as aggregation or access switches in large networks, or as core switches in smaller networks.
Standalone versus stackable switches
A standalone switch is managed and configured with a set capacity. Stackable switches can be connected to increase capacity and network availability.
For configuration, troubleshooting, and management, a stack of switches can be treated as a single unit. If any part of the stack fails, transmissions will be routed around the failure, preventing a network bottleneck.
Gigabit switch features
Power over Ethernet (PoE)
PoE is a technology that allows devices and endpoints to be powered through their Ethernet connections, rather than traditional AC or battery power. That greatly increases the flexibility and reach of connected systems, which has contributed to a wave of innovation in smart buildings.
Security
Many Ethernet switches have built-in support for security features such as segmentation and hosting firewalls.
Number of connections
The number of ports provided in a switch can vary widely. The more network users and endpoints in use, the more ports will be needed. Fixed-configuration switches are typically available with 4 to 52 ports. Modular switches scale to hundreds of total ports.
Application hosting
Application hosting is now possible with some modern gigabit switches, giving developers increased options for improving network performance. For example, locating an application on a switch at the network edge might help deliver a better user experience. Also, a distributed computing application hosted on a switch in a smart building environment might make its systems more responsive.
Multigigabit technology
If speeds greater than 1 Gbps are to be achieved with legacy wiring, then the gigabit switch in use will need to be compatible with Multigigabit technology and/or be capable of speeds of 5 or 10 Gbps.