Although a router, switch, and hub help drive network traffic, devices send packets in different ways. Find the differences between these network devices.

Although routers, switches, and hubs are all network devices, they all serve different purposes.
A network hub is a node that transfers data to each computer or Ethernet-based device connected to it. A switch is a device that channels data received from any of several input ports to the specific output port that will take them to their intended destination.

A router is a physical or virtual device that transmits information between two or more packet computer networks - analyzing the destination IP address of a given data packet, calculating the best way to reach it and directing accordingly. .

Let's explore these devices further. First, we will look more closely at the difference between hubs and switches, and then compare and contrast the switches and routers.

Hubs vs. switches

Early Ethernet networks did not have the concept of a virtual LAN (VLAN). Thus, a whole network consisted of a single IP subnet. If you want to connect two or more devices to the LAN using Ethernet, you will use a network hub.

A hub is simply a multi-port Ethernet repeater that works on the physical segment - or layer 1 - of the OSI model. When the hub collects information from a sending device, it merely repeats or transmits the same information from all hub ports.

The device connected to the hub for receiving the information receives it. However, all other connected devices as well. These devices ignore unnecessary transmissions. That said, a hub is fast becoming an inefficient way to carry communications as the number of connected devices increases.

For this reason, the network switch was invented. A traditional switch operates on the data link segment - or layer 2 - of the OSI model. Switches offer two main features that set them apart from hubs.

How does a network switch  works

First, switch can segment the network into multiple logical LAN networks known as VLANs. This segmentation divides a LAN with a single broadcast domain into multiple broadcast domains. This helps reduce the amount of traffic congestion broadcast on larger networks.

Then, a Layer 2 switch can maintain a static or dynamic table that lists the port number of the switch along with the MAC Access Media (MAC Access) address of the attached device. The advantage is that the switch no longer has to retry communications on all Ethernet ports. Instead, the switch will look for the Ethernet frame received by the distribution device. The framework will contain a destination MAC address, cross-referenced in the switch's MAC address table. If the switch knows the specific port to which the MAC address corresponds, it will be sent just outside the port, as a unicast frame.

Routers vs Switches

Switch versus router, as mentioned earlier, Layer 2 switches can separate a single LAN into multiple VLANs. Each VLAN is its IP subnet. Devices on the same VLAN and IP subnet can communicate at level 2 without any additional works. However, if device on VLAN 10, for example, wants to communicate with a device on VLAN 20 - this is known as interVLAN routing - then a router operating on the network or layer 3, the OSI model segment, is required. 

Instead of switching frames using MAC addresses, routing between subnets uses IP addresses that are in IP network packets that encapsulate Ethernet frames with the source IP address and destination information. Traditionally, a dedicated router provided routing services for level 2 switches. 

However, a more modern approach in corporate networks is to use Layer 3 switch, which combines routing and switching functions in a single device.