What's the difference between hub and switch ?

Hubs

1) contains multiple ports. When a Packets arrives at one port, it is copied to the other ports so    that all segments of the LAN can see all packets.

2) operate at the Physical layer (layer1)  of the OSI Reference Model

3) there is collision in Hub network and use CSMD(carrier sense collsion detection to avoid collision)

4) the network bandwidth is shared

5) Hub is less secure since every packet is broadcast to every port

Switches

1)  filters and forwards packets between LAN segments

2)  operate at the data link layer (layer2)  of the OSI Reference Model

3) there is no collision in swiched network

4) switch learn mac addrese and make swichind Decision based on mac table

A hub is a layer1 device (Physical Layer) it doesnt learn mac-address so its a passive device , so when a message is received to a hub it floods it throgh all the ports except the soruce port, whereas a swithch is a layer2 device (Data link layer) it learns mac-addresses and stores them in its mac address table so its an active device , so when a unicast message is arrived to a switch it reads the destination mac-address search for it in the mac table and forwards it throught the port that this mac address is mapped to it in the MAC Table. when it recieves a multicast or a broadcast message all it to is that it floods this message through all its port except the source port. so a switch is has1 Broadcast message unless Vlans is created in it and has number of collision domain = to the number of its ports. whereas a HUB has1 broadcast and collision domain ....

Through that you can see that a switch is a more intelligent device that is able to exchange data within a LAN.

Hope its clear now for you ....

Hassan Mehsen

In simple words:

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A "Hub" retransmits a recieved packet to every machine connected to it on every port. Which means much more traffic and collisions.

A "Switch" retransmits a recieved packet to it's specific destination. Minimum traffic and no collisions.

Here you go with little brief about Hubs,Switches ..Hope this helps you

A switch is effectively a higher-performance alternative to a hub. This article describes hubs in more detail. People tend to benefit from a switch over a hub if their home network has four or more computers, or if they want to use their home network for applications that generate significant amounts of network traffic, like multiplayer games or heavy music file sharing. In most other cases, home networkers will not notice an appreciable difference between a hub and switch (hubs do cost slightly less)

Technically speaking, hubs operate using a broadcast model and switches operate using a virtual circuit model. When four computers are connected to a hub, for example, and two of those computers communicate with each other, hubs simply pass through all network traffic to each of the four computers. Switches, on the other hand, are capable of determining the destination of each individual traffic element (such as an Ethernet frame) and selectively forwarding data to the one computer that actually needs it. By generating less network traffic in delivering messages, a switch performs better than a hub on busy networks.

Hub

Switch

Layer

Physical layer. Hubs are classified as Layer1 devices per the OSI model.

Data Link Layer. Network switches operate at Layer2 of the OSI model.

Ports

4/12 ports

Switch is multi port Bridge.24/48 ports

Transmission Type

Hubs always perform frame flooding; may be uncast, multicast or broadcast

First broadcast; then uncast & multicast as needed.

Table

A network hub cannot learn or store MAC address.

A network switch stores MAC addresses in a lookup table.

Device Type

Passive Device (Without Software)

Active Device (With Software) & Networking device

Transmission Mode

Half duplex

Full duplex

Broadcast Domain

Hub has one Broadcast Domain.

Switch has one broadcast domain [unless VLAN implemented]

Used in (LAN, MAN, WAN)

LAN

LAN

Data Transmission form

Electrical signal or bits

Frame (L2 Switch) Frame & Packet (L3 switch)

Function

To connect a network of personal computers together, they can be joined through a central hub.

Allow to connect multiple device and port can be manage, Vlan can create security also can apply

Definition

An electronic device that connects many network device together so that devices can exchange data

A network switch is a computer networking device that is used to connect many devices together on a computer network. A switch is considered more advanced than a hub because a switch will on send msg to device that needs or request it

Collisions

Collisions occur commonly in setups using hubs.

No collisions occur in a full-duplex switch.

Spanning-Tree

No Spanning-Tree

Many Spanning-tree Possible

Manufacturers

Sun Systems, Oracle and Cisco

Cisco and D-link

Simple way !!

A hub is dummy which sends all the packets it receives to all of its ports connected where as switch has the mac table and it learns mac address of the connected devices and sends the packets accordingly

A hub is a multi-port repeater wihile a switch is a multi-port bridge.