Hubs and Switches

HUB

• It works at Layer 1
• It is not a intelligent Device.
• A hub is nothing more than a physical repeater, if it receives an electrical signal on one interface it will repeat it by sending it on all its interfaces except the one it originated from.
• It Creates Collision in the network.
• Larger the Network, higher the collision.
• Hub operates at Half-duplex mode.
• It has Single collision Domain and Single Broadcast Domain.

SWITCH

• It works at Layer 2.
• It is a Intelligent device.
• Switch works at both Half-duplex and Full-duplex mode.
• If it receives a packet, Instead of sending to all the interfaces, it forwards it to the concerned Interface the MAC belongs.
• Hence it avoids, collision in the Network.
• Switch has Multiple Collision and Single Broadcast Domain.

SWITCHING MODES

• Cut-through

  The switch will start forwarding the frame before the whole frame has entered the switch, It only needs the Destination Mac-Address. This is fast but less reliable if you have corrupt frames.

• Store-and-forward

The switch will receive the complete frame, check if it’s errors free and then forward it. If it’s corrupt it will be discarded.

• Fragment-free

                                The switch will check if the first 64 bytes are OK, basically this is between cut-through and store-and-forward switching.

You can also Look into my Video Tutorial: