The differences are as follows:

1, different functions

Layer 3 switches are switches with specific router functions. Generally speaking, Layer 3 switches are layer 2 switches and hardware routers.

2. Different working layers

The three-layer switch works in the third layer of the osi network standard model: the network layer.

Layer 2 switches works in the second layer of osi network standard model: data link layer.

In the enterprise network and teaching network, the core layer of the network generally adopts a three-layer switch, and the gigabit or 100M port on the three-layer switch is used to connect different subnets or VLAN.

In the practical application process, the typical method is that the interconnection of subnets in the same local area network and the routing between VLAN in the local area network use three-layer switches instead of routers, and only when the interconnection between local area network and public network requires cross-regional network access can professional routers be used.

Extended data:

Layer 3 switches do not stack routers directly on Layer 2 switches. The three-layer switch divides the hardware into two areas: the control plane with routing and management functions and the data plane with data forwarding functions to realize fast packet forwarding.

The traditional router has the routing function, packet forwarding and management function processed by cpu, and the load of management function increases, which will lead to the decrease of packet forwarding ability.

Baidu Encyclopedia-Layer 3 Switch