subject: Switching Or Routing? From The Technical Applications In Choice - Switches, Routers - Education [print this page] Many faces core network transformation network may encounter this problem: the core network switch or router device is selected?
, Of course, the problem in the above mentioned switches is three and four switches, because the three below the traditional network switching equipment does not have the core network equipment, management and routing functions, while the router is also the enterprise level is relatively high-end routers.
In fact, faced with this problem, only the light of network switching and routing technology to compare operating principle, combined with the actual needs of the enterprise network program can make the right choice.
1, the router works Many industry friends have a misconception that working in the third OSI layer?? Network layer router, a network switch to a certain stage of development, in order to solve the traditional network switch can not complete the core function of the network generated, it is not true: early In March 1986, Cisco to Utah State University in the United States provides the world's first named AGS router, since then, rapid progress of network communication and the original distribution of the different blocks in the country co-Lan network formed Wan network of global coverage.
Router name from the English Router, by definition, can be simply understood as the path through the network, its Internet data transfer works as follows:
1) Direct receiver terminal within the network, switching equipment and other sources of transmission of data frame A, using link layer function modules, verify the integrity of the data frame;
2) stored under the router, including its own IP and other network equipment, IP address correspondence table, the control data frame received the ultimate goal in the IP header IP address, network traffic congestion, according to state information, query optimization path, the data frame to determine the purpose of the next step to reach this IP address IP address and write, re-calculated checksum value;
3) B data frame is encapsulated in the IP address, the physical interface to the outside network through the established purpose of the next level IP address to send;
4) long-distance route through the transmission of data frames N to the destination router, the router for the received large amounts of information to filter the same time, the source address of data frame transmission and N through the check, the router by reading routing table with the port in the IP data frame information corresponding N, N decided to send the data frame to its corresponding VLAN, ARP protocols via IP information to resolve MAC address information, the purpose of inward network devices to send or to sent within the network switching equipment, switching equipment and then stored in accordance with the port corresponding to the MAC address table, through the appropriate port to send to the terminal.
Router data from the above works is not difficult to see the router at the WAN and WAN Unicom point position, the process of sending and receiving circuit transmission can achieve, which laid the basis for its position as the network core. In fact, many large enterprises will realize the router cascade, at this time, in addition to the core routers within the network from the device outside, it is as connected LAN and WAN equipment.
, Of course, the working group level and individual access router in the WAN and the WAN connection only with the basic routing forwarding, firewall, radio and other functions can be isolated, while the enterprise-class router with security in mind, the effective transmission of data, IP effective use of resources and other factors, through the management software to receive data frames up to match the checksum, internal network through multiple access ports for VLAN VLAN classification and management and implementation of information exchange between, and to provide strategic management of IP improve the function of fire intensity to enhance the network security is a must, and control large-scale network transmission quality QOS quality of service management capabilities will also be a big help, but even with multiple network interface support can achieve a variety of terminals, which , the router supports multiple routing protocols, network protocols is essential.
