The technology of the Layer 3 switch is becoming more and more mature and its applications are becoming more and more extensive. In a certain range, it has more advantages than routers, but there is still a big difference between the three-layer switch and the router. In the local area network, the three-layer switch has obvious advantages.

1. The transmission bandwidth between subnets can be arbitrarily allocated:

In a traditional router, each serial port can be connected to a subnet, and the rate of this subnet transmitted through the router is directly limited by the interface bandwidth. The difference is that the third layer switch defines multiple ports as a virtual network (VLAN), uses a virtual network composed of multiple ports as a virtual network interface, and sends the information in it to the third layer through the ports that constitute the virtual network. Switches, because the number of ports can be arbitrarily specified, the transmission bandwidth between subnets is not limited.

2. Reasonable allocation of information resources

Because the network system connected by the third-tier switch is used, the resource rate of the access subnet is no different from the resource rate of the global network, so it is meaningless to set up a separate server. By directly establishing a server cluster in the global network, under the premise of ensuring the transmission rate of the broadband intranet, it can not only save costs, but also make full use of the advantages of the software and hardware resources of the cluster server, and can more rationally configure and manage various information resources. This problem is difficult to solve in router networking.

3. Reduce costs

In enterprise network design, because people usually only use two layers of switches to form the same broadcast domain subnet, routers are used to connect each subnet, making the enterprise network form an intranet, and routers are expensive, so enterprises supporting intranets The network cannot reduce equipment costs. Now, in the inline network system, people use the third layer switch for network design, not only can the virtual subnet be arbitrarily divided into subnets, but also can complete the communication between the subnets through the three-layer routing function of the switch , That is, the establishment of subnets and inline subnets can be completed by switches, which greatly saves expensive routers.