Traditional switches can no longer meet the demands of Internet cafe networks. Today, Layer 2 switches are used, which operate at the second layer of the OSI model, the Data Link layer.
As a hot topic for Internet cafes, we mainly discuss the differences between Layer 2 switches and routers.
1. Subnet Division: Switches can only recognize MAC addresses.
A MAC address is a physical address with a flat addressing structure, so it cannot be used to divide subnets. Routers, however, recognize IP addresses. An IP address is assigned by the network administrator, is a logical address, and has a hierarchical structure divided into a network ID and host ID, making it very convenient for subnetting. The primary function of a router is to connect different networks.
2. Loops: Based on a switch’s address learning and station table algorithms, loops are not allowed between switches.
If a loop exists, the Spanning Tree Algorithm must be initiated to block the port causing the loop. Router routing protocols do not have this problem; multiple paths can exist between routers to balance the load and improve reliability.
3. Broadcast Control: Switches can only reduce collision domains, not broadcast domains.
An entire switched network is one large broadcast domain, and broadcast packets spread throughout the switched network. Routers can isolate broadcast domains, meaning broadcast packets cannot pass through a router to continue broadcasting.
4. Load Concentration: Switches can only have a single path between them, concentrating information on one communication link and preventing dynamic distribution to balance the load.
Router routing protocol algorithms can avoid this. The OSPF routing protocol algorithm, for instance,