What is the role of a router?

What is the role of a router? What is the difference between it and switches and bridges?

A: One role of a router is to connect different networks, and the other is to select an information transmission line. Selecting smooth and fast routes can greatly improve the communication speed, reduce the communication load of the network system, save network system resources, and improve the network system accessibility rate, so that the network system can exert greater benefits.

From the perspective of filtering network traffic, the role of a router is very similar to that of a switch and a bridge. However, unlike switches that work on the physical layer and divide network segments physically, vrouters use specialized software protocols to logically divide the entire network. For example, a router that supports the IP protocol can divide the network into multiple sub-network segments. Only network traffic directed to a Special IP Address can pass through the router. For each received packet, the router recalculates its verification value and writes it to a new physical address. Therefore, the speed of data forwarding and filtering by vro is usually slower than that of A vswitch that only views the physical address of a data packet. However, vrouters can improve the overall efficiency of networks with complex structures. Another obvious advantage of a vro is that it can automatically filter network broadcasts. In general, the installation process of adding a vro to a network is much more complex than that of a plug-and-play vswitch.

Generally, a vro should be used to connect a heterogeneous network to multiple subnets.

The main task of a router is to find an optimal transmission path for each data frame passing through the router and transmit the data to the destination site effectively. It can be seen that the routing algorithm is the key to selecting the optimal path. To achieve this, the route Table Routing Table is stored in the router for Routing selection. The path table contains the subnet flag information, the number of online routers, and the name of the next router. The path table can be set by the system administrator or dynamically modified by the system. It can be automatically adjusted by the router or controlled by the host.

1. Static path table

The system administrator sets a fixed path table in advance to call it a static path table. Generally, it is set in advance according to the network configuration during system installation, it will not change as the network structure changes in the future.

2. Dynamic Path table

Dynamic) the path table is automatically adjusted by the router according to the running status of the network system. The router selects the Routing Protocol) to automatically learn and remember the network running status, and automatically calculate the optimal path for data transmission as needed.