Ethernet hub

Description

An Ethernet hub, active hub, network hub, repeater hub, multiport repeater, or simply hub is a network hardware device for connecting multiple Ethernet devices together and making them act as a single network segment. 

When referring to a network a hub is the most basic networking device that connects multiple computers or other network devices together. Unlike a network switch or router a network hub has no routing tables or intelligence on where to send information and broadcasts all network data across each connection. Most hubs can detect basic network errors, such as collisions, but having all information broadcast to multiple ports is a security risk and cause bottlenecks. In the past, network hubs were popular because they were cheaper than a switch or router. Today, switches do not cost much more than a hub and are a much better solution for any network.

A hub is a physical layer networking device which is used to connect multiple devices in a network. They are generally used to connect computers in a LAN. A hub has many ports in it. A computer which intends to be connected to the network is plugged in to one of these ports.

Types of Hub

There are three types that are deployed according to their usage. They are passive, active, and intelligent. In recent days, the modification was done to hubs that provide high performance.

1. Passive Hub

• It has quiescent creatures as the name portraits, and it does not impact performance, but it helps identify the bugs and detect the faulty hardware. They are a simple that receives the packet on a port and is then broadcast to all the port.
• It has a 10base-2 port and RJ-45 connectors, which is connected to each local area network device. This connecter is applied as a standard one in your network. AUI ports are placed in advanced passive hubs, which are connected as the transceiver as per the network design.

2. Active Hub

• They have some additional features apart from passive hubs. It monitors the data which is sent out to the connected devices. It has a unique role in this network communication by using Store technology to check the data before sending it out and prioritising which packet to send first.
• It has the option to fix the damaged packets and hold the direction and distribution of the rest of the packets. If a week signal is received in port, but it’s still readable, then the active hub amplifies it to a stronger signal before its retransmitted to other ports.
• If any connecting device is not functioning in the network, it can boost the signal, which other devices view with passive hubs. Hence it helps in the continuation of service in the local area network.
• But few of them will account for the malfunction of any device and offer related diagnostic capabilities in the local area network. They will be able to resync the packets and transmit them again. Some cables go through electromagnetic troubles and stop the packet from entering into the designated port, or rarely it does not reach the port. At those times, they can make up for the packet or data loss. They are accessible to retime the port for slower delivery and error-prone connections.

3. Intelligent Hub

• These give many advantages than passive and active hubs. The management who wants to expand their business in networking can assign users to share a common pool efficiently and work more quickly using intelligent hubs. The technique behind them is explored recently, and now its great demand in the market.
• It is proved that it delivers unparallel performance for your local area network. If any problem is detected with any physical device, it is easily detected, diagnosed, and solved using management data that the hub can rectify.
• This is a standard improvement over active hubs. Detecting the centralized management tool helps to explore the network that runs out of the device to find the low functioning devices.
• Another feature is flexibility which has high transmission rates to numerous devices. They have their standard terms with transmission rate as 10, 16, in the speed of 100Mbps to desktop.

WHAT IS A SWITCH?

A network switch is networking hardware that connects devices on a computer network by using packet switching to receive and forward data to the destination device. A network switch is a multiport network bridge that uses MAC addresses to forward data at the data link layer of the OSI model

How does a network switch work?

Once a device is connected to a switch, the switch notes its media access control (MAC) address, a code that’s baked into the device’s network-interface card (NIC) that attaches to an ethernet cable that attaches to the switch. The switch uses the MAC address to identify which attached device outgoing packets are being sent from and where to deliver incoming packets.

So the MAC address identifies the physical device as opposed to the network layer (Layer 3) IP address, which can be assigned dynamically to a device and change over time.

When a device sends a packet to another device, it enters the switch and the switch reads its header to determine what to do with it. It matches the destination address or addresses and sends the packet out through the appropriate ports that leads to the destination devices.

To reduce the chance for collisions between network traffic going to and from a switch and a connected device at the same time, most switches offer full-duplex functionality in which packets coming from and going to a device have access to the full bandwidth of the switch connection. (Picture two people talking on a cell phone as opposed to a walkie-talkie).

While it’s true that switches operate at Layer 2, they can also operate at Layer 3, which is necessary for them to support virtual LANs (VLAN), logical network segments that can span subnets. In order for traffic to get from one subnet to another it must pass between switches, and this is facilitated by routing capabilities built into the switches.

Types of switches

Switches vary in size, depending on how many devices you need to connect in a specific area, as well as the type of network speed/bandwidth required for those devices. In a small office or home office, a four- or eight-port switch usually suffices, but for larger deployments you generally see switches up to 128 ports. The form factor of a smaller switch is an appliance that you can fit on a desktop, but switches are also rack-mountable for placement in a wiring closet or data center or server farm. Sizes of rack-mountable switches range from 1U to 4U, but larger ones area also available.

Switches also vary in the network speed they offer, ranging from Fast ethernet (10/100 Mbps), Gigabit ethernet (10/100/1000 Mbps), 10 Gigabit (10/100/1000/10000 Mbps) and even 40/100 Gbps speeds. Which speed to choose depends on the throughput needed for the tasks being supported.

Switches also differ in their capabilities. Here are three types.

Unmanaged

Unmanaged switches are the most basic, offering fixed configuration. They are generally plug-and-play, which means they have few if any options for the user to choose from. They may have default settings for features such as quality of service, but they cannot be changed. The upside is that unmanaged switches are relatively inexpensive, but their lack of features make them unsuitable for most enterprise uses.

Managed

Managed switches offer more functionality and features for IT professionals and are the type most likely seen in business or enterprise settings. Managed switches have command-line interfaces (CLI) to configure them. They support simple network management protocol (SNMP) agents that provide information that can be used to troubleshoot network problems.

They can also support virtual LANs, quality of service settings and IP routing. The security is also better, protecting all types of traffic that they handle.

Because of their advanced features, managed switches cost much more than unmanaged switches.

Smart or intelligent switches

Smart or intelligent switches are managed switches that have some features beyond what an unmanaged switch offers, but fewer than a managed switch. So they are more sophisticated than unmanaged switches, but they are also less expensive than a fully manageable switch. They generally lack support for telnet access and have Web GUIs rather than CLIs. Other options, such as VLANs, may not have as many features as those supported by fully managed switches. But because they are less expensive, they may be a good fit for smaller networks with fewer financial resources and those with fewer feature needs.

DIFFERENCE BETWEEN A HUB AND A SWITCH

KEY DIFFERENCES

• A Hub is a networking device that allows you to connect multiple PCs to a single network, whereas a Switch connects various devices together on a single computer network.
• A Hub operates on the physical layer, whereas Switch operates on the data link layer.
• Hub uses Half-duplex cable on the other hand Switch uses Full duplex cables
• Hub is a passive device while the switch is an active device
• Hub uses electrical signal orbits while switch uses frame & packet
• Hub and switch are both used in LAN

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