Hub & Switch Operating Principles and Differences

 

In this session, we will learn about the operating principles and differences between hubs and switches. Now, hubs are gone, but if you're a network engineer, you should know the operating principles of hubs and switches and the difference between them, right?

 

 

1. HUB

 

 

- Equipment corresponding to 1 layer of OSI 7 Layer

 

- Equipment used before the switch came out (hard to find now)

 

- Ethernet CSMA/CD method (can't be used by multiple users at the same time, only one person)

 

 

★ Principle of motion (think deeply and read slowly)

 

Now! I'm going to talk about how a 24-port hub works. If you send data from port 1 to port 3, the hub sends the data to 23 ports except port 1 (which is broadcast), and 23 ports receive the data and go to each connected LAN card.

 

Then, the LAN card opens the packet, sees the destination ip address, receives the data if it suits you, and throws it away if it doesn't.

 

The reason I'm looking at the ip is that the first port PC to send it to the destination MAC because I don't know the MAC address of the third port PC. But I know the destination ip.

 

That's why the LAN card looks at the IP. The hub just sends the incoming data to everywhere, like an electrical signal 01010 (broadcast).

 

Then the LAN card does the rest.That's why hubs are called tier one, but hubs don't have MAC tables.

 

Because I don't make it and send it to all ports unconditionally, so port 1 here refers to the LAN card of the pc bitten by the port, not thinking about the port.

 

 

 

 

2. Switch

 

 

: Equipment corresponding to 2 to 7 layers of OSI 7 layers

 

★ Principle of motion (think deeply and read slowly)

 

Let me explain how the 24-port switch works. When you send data from port 1 to port 3, the switch first opens the packet sent from port 1 and learns the source MAC from the switch's MAC table.

 

Since I don't know the MAC of the port 3 PC, which is the destination. The switch will send data to all ports (flooding) This time, if you send data from port 2 to port 4, the switch first opens the packet sent from port 2 and learns the source MAC to the switch's MAC table.

 

I don't know the MAC of destination D.Flooding. If all ports communicate once, the switch's MAC table will be completed. From now on, it's really... It performs the function of the switch.

 

This is how the Collision Domain is divided for each port. Like hubs, the switch first sends data to all ports and then acts as a real switch only when the MAC table is completely completed.

 

From then on, if port 1 sends data to port 3 to port C, the switch does not flood because it knows the destination MAC, but forwards the data to C.And I also filter so that I can't go to the rest of the ports.

 

 

 

※ Hub to Switch Differences

- When ten people use data at the same time, the hub can communicate with only one node, and the switch can communicate with multiple nodes.

 

- Hub does not have a separate setting function, switch can be vlan and multiple settings.

 

We looked at the operating principles and differences between hubs and switches. If you don't know, it'll be easier to understand if you follow along while drawing.

 

 

 

 

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