What is the difference between Layer 2 and Layer 3 switches?

1. Different working levels:

Layer 2 switches work at the data link layer, and Layer 3 switches work at the network layer. Layer 3 switches not only achieve high-speed forwarding of data packets, but also achieve optimal network performance according to different network conditions.


2. The principle is different:

The principle of a layer 2 switch is that when the switch receives a data packet from a certain port, it will first read the source MAC address in the packet, then read the destination MAC address in the packet, and look up the corresponding port in the address table. , if there is a port corresponding to the destination MAC address in the table, copy the data packet directly to this port. The principle of the Layer 3 switch is relatively simple, that is, one route is exchanged multiple times. Generally speaking, it is the first source-to-destination route. Source to destination can be exchanged quickly.


3. Different functions:

The Layer 2 switch is based on MAC address access, only forwards data, and cannot be configured with an IP address, while the Layer 3 switch combines the Layer 2 switching technology with the Layer 3 forwarding function, which means that the Layer 3 switch is based on the Layer 2 switch. The routing function is added to the above, and the IP addresses of different vlans can be configured, and the communication between vlans can be realized through three-layer routing.


4. Different applications:

Layer 2 switches are mainly used at the network access layer and aggregation layer, while Layer 3 switches are mainly used at the core layer of the network, but there are also a small number of Layer 3 switches used at the aggregation layer.


5. The supported protocols are different:

Layer 2 switches support physical layer and data link layer protocols, such as Ethernet switches and Layer 2 switches. The HUB has similar functions, while Layer 3 switches support physical layer, data link layer and network layer protocols.

L3 Fiber Switch

Post time: Sep-16-2022