Principle and configuration of layer 3 switch

Three-layer switching technology

(1) using layer 3 switching technology to realize the communication between VLAN

(2) layer 3 switching = layer 2 switching + layer 3 forwarding

Three-layer exchange

Learn layer 2 rewriting information from the layer 3 engine to create a MLS entry in the hardware

Responsible for rewriting and forwarding subsequent packets in the data flow

MLS entry

MLS based on CEF,CEF is a model based on topology forwarding.

(1) forwarding information base (FIB), which is composed of host ip and switch ip

(2) adjacency table, which consists of host MAC and switch MAC

Experimental environment

1. The experimental topology diagram is as follows: interworking between PC1, PC2 and PC3 of the external network through a layer 3 switch.

2. Experimental process

(1) turn on the layer 2 switch sw-2 and set the interface mode

(2) set the interface address of the cloud router. Because the router on the topology diagram has only one network cable connected to the external network, set the router as a default route.

(3) set up layer 3 switch sw-3

3. Experimental results

PC1 interconnects with PC2 and PC3, and the experiment is successful.