Analysis of Router basic configuration and data transmission

In the current era of rapid development of the network, routers have a pivotal role. Because the router acts as the relay system in the network layer, it provides a routing and forwarding function of the data between the third layer network. Therefore, the router's function, role and basic configuration are as members of IT industry we must be proficient.

Below, we will make a brief analysis of the router from two aspects: that is how to build a simple network environment in the experiment, and the situation and corresponding solution in its configuration, as well as the application of different data encapsulation protocols (HDLC and PPP) to the transmission in the Internet. Link compression For comparison of transmission rates.

Router configuration and network set-up

To build a network, it is necessary to have a clear understanding of the network structure in the application, and the correct connection in physics, the allocation of IP address in the router, the choice of the WAN routing protocol and the access of LAN are all important to be paid attention to in the practical application. Here are the three main areas that we've experimented with to make the entire network run.

One, the physical connection between the net

In our experimental environment, using the simplest point to point environment, through a pair of modems to connect the WAN port of the two routers for data transmission. The modem connects the twisted pair (straight line), and also gives the bandwidth of the transmission line. In the LAN port, the router is connected directly with a computer. But in the actual application, often not only two routers are connected, or multiple routers, switches, hubs and so on. This depends on the network structure to the number of network equipment, location, according to the environment and requirements for further consideration.

Second, the router configuration

Because today's routers contain more than just the concept of data forwarding and routing, it can also implement a variety of meanings and functions, such as security restrictions, flow control, and so on. So here's a brief introduction to some of the steps to implement its original functionality. First, enter the port mode, give each WAN port and Ethernet port an IP address and the corresponding address mask. Secondly, in the WAN port to set bandwidth and Data Link Transport Package protocol (in the experiment we used the HDLC and PPP protocol respectively). Finally, to configure routing protocols, there are many different protocols (static routing, dynamic OSPF, EIGRP) that can be selected in large networks. And we are using Cisco's proprietary dynamic routing protocol EIGRP.

Third, the user terminal setting

For the convenience of experiment, we only put a microcomputer in Ethernet to connect with Ethernet port. All devices that are connected from the Ethernet port must assign an IP address to the same network segment as the Ethernet port of the router, and the Ethernet port of the router is used as the gateway to ensure the normal exchange of information between Ethernet and the network segment.

Through the above three point configuration, the experimental network can be run up. Ping command can be used to detect the normal communication between the two computers. But in the course of the experiment, in each of these aspects, there are a lot of small places to pay attention to. The following are some of the experiences we have gained in our experiments.

A. The ascom of the connection in the WAN is intelligent, so the communication can be made after the clock of two modems is synchronized after the connection. However, it is important to note that the modem will be customized a main one from or manual settings can also, when the main modem changes the rate of transmission, the link automatically disconnected, from the modem will be with the main modem clock resynchronization to the new set rate of communication.

Two. In the port status check of the router, when the interface is connected with the Allied device, the port is up and the protocol status of the port is up when the Allied device is turned on and the link protocol is configured to complete.

Three. When configuring the routing protocol, if the Protocol is not up, check the status of the router is all the ports are up, but the link does not pass. This is because the router does not send the next device routing information to the router's routing table, data forwarding can only through the routing table on the router to find directly connected to the network segment is not able to find the next hop connected network segment address. Only after the normal operation of the protocol, the router learns the route of the network through the routing protocol in order to forward the resulting data to its next hop. Also note that when routing protocols are used, the designation of the network number refers to the entire network using this routing protocol.

Four. Router WAN Data Link Layer Packaging protocol to synchronize, is to send and receive data must use the same kind of encapsulation protocol, otherwise the WAN will lose the interface package with different types of packets, resulting in links to the impassability.

Five. Since the interface between the computer and the router belongs to the same kind of network access equipment, it should be connected with the reverse twisted pair (crossover line). In the same case, the switch is connected to the hub. It can also be determined by the identity of the port. The same identification with the intersection line, on the contrary, with straight line.