Layer-3 Ethernet Switch

       With the popularization of layer 3（L3） switching technology, the application environment of L3 switches has

moved forward from the network core layer to the convergence layer or even the edge layer, especially in the

finance, education and transportation industries.   

       Although the common layer 2( L2 ) switch can realize the fast forwarding of data, it does not have the function

of routing and forwarding and dividing the broadcast domain. The router can divide the broadcast domain, but it

can't transmit the data quickly. The performance of the L3 switch just makes up for the above shortcomings. It has

both the function of L3 routing and the network speed of L2 switching, which just meets this demand.   

             From a medium-sized campus network to the backbone of the enterprise, the backbone of the MAN, the

convergence layer is the use of L3 switches. Its application is also from the initial backbone layer, the convergence

layer has penetrated to the edge of the access layer. In the current popular broadband network construction, the

L3 switch is generally placed in the center of the community and the convergence layer of multiple communities.

The appearance of L3 switch has greatly changed the performance of local area network. Just as routers dominate

the WAN, three-tier switches will dominate the LAN in the future.