Points for attention of network management in the maintenance work of LAN

Users who use the LAN office often use the network to print materials and access files. For some reason, the speed of network access may be abnormal, then we tend to mistakenly think that the cause of the lower network speed is likely to be a bottleneck in some devices, such as NIC, switch, hub and so on, in fact, the most impact on the speed of the server's hard drive. Therefore, the proper configuration of the server's hard disk in LAN will greatly improve the network performance of the whole LAN. In general, we need to consider the following factors when setting up a hard disk:





server in the hard drive should be as fast as possible, the type of large capacity, because the hard disk speed, access to the server data on the network faster;




The hard disk interface in the
server is preferably a SCSI model, because it is faster than the IDE or Eide interface transmits data, and it transmits and accepts data in a parallel mode of data transmission;





If the conditions permit, we can install the hard disk array card to the network server, because the hard disk array card can greatly improve the read and write performance and security of the hard disk;





Of course Here you should also note that in the same SCSI channel, do not use Low-speed SCSI devices (such as CDs) with the hard disk, otherwise the SCSI interface of the hard drive data performance will not be played.





correct use of the "bridge" device





"Bridge" devices are typically network devices for the same network segment, while routers are network devices for different sections. The author's unit, once installed a set of microwave networking equipment, physical equipment Unicom, the Internet debugging, the server always prompt the current network segment number should be the other side of the network section number. When the server's network segment number is changed to the same as the other, the server's alarm disappears. This is a set of equipment with bridging properties. Later, with another site installed microwave networking equipment, exchange with another manufacturer's products, in the connection before we will be on both sides of the network section number to be consistent, can be installed after the device, the server again appeared the alarm: the current routing error. After modifying the network segment on one side, the alarm disappeared. This shows that the proper distinction between "routing" devices and "bridge" devices is important in setting network parameters.





follow the rules to connect





Connect the local area network each computer is uses the twisted pair line to realize, but does not use the twisted pair to connect the two computers simply mutually, can realize the communication goal, we must follow the certain wiring rule to carry on the connection. The author has tried to two 100 meters away from the computer with twisted pair of cables to connect, so as to achieve communication, but no matter how efforts are not connected successfully, and then by the expert pointing, twisted-pair connection distance can not exceed 100 meters. In addition, if we need to connect to more than 100 meters of two computers, must use the conversion device, when connecting the conversion device and switch, we must also do jumper. This is because in Ethernet, in general, the use of two pairs of twisted-pair, arranged in 1, 2, 3, 6 position, if the use is not two pairs of lines, but the original pair used by the line used separately, will form a string around, resulting in a larger crosstalk (NEXT). Has a great impact on network performance. 10M network Environment This situation is not obvious, 100M network environment if the flow of large or long distance, the network will not be able to unicom.





strictly enforce grounding requirements





because in the local area network, transmission are some weak signals, if the operation is slightly improper or not in accordance with the specific operating requirements of network equipment to do, it may be in the network interference information, serious can lead to the entire network impassability; In particular, some network transfer equipment, due to the remote line, It is very strict grounding requirements, otherwise the network equipment will not reach the specified connection rate, thus in the process of networking to produce a variety of inexplicable fault phenomenon. The author has no intention to plug the power of the router in the mains socket, the result 128K DDN line is unable to and the Internet Unicom. The Telecommunications bureau to check the line is very normal, and finally check the router power 0 voltage, found wrong, switch back to the UPS socket, everything back to normal. Another time, the router's power plug grounding end of the broken, resulting in data packets are often lost, do ping connection, when good and bad, replace the power cord after all normal. This shows that we use the network equipment, must be in the equipment under the conditions of the condition, otherwise it will bring us a lot of trouble.





Use the new network card with good quality and fast speed





In the local area network, the computer cannot communicate with the computer is very normal matter, causes the breakdown reason may have many. I have statistics, the local area network fault most of the network card-related, or the NIC is not properly installed, or network line contact is bad, there may be an older network card, can not be correctly recognized by the computer, and also some network cards installed in the server, can not withstand the impact of large-capacity data, and eventually scrapped. Therefore, in order to avoid the above phenomena, we must be willing to invest, if the network card is installed in the server, be sure to use the quality of the network card, because the server is generally uninterrupted operation, only the quality of a good network card can be a long time to "work", in addition, because of the large capacity of the server transmission data, So we purchased the capacity of the network card must match, so as to achieve "good horse with a good saddle."





reasonable set up switch





switch is an important data exchange device in the local area network, the correct and reasonable use of the switch can also improve the data transmission performance. The author has configured the switch port to 100M Full-duplex, and the server installed a model for intel100m EISA network card, after the installation of all normal, but in the large flow load data transmission, the speed becomes extremely slow, and finally found that this network card does not support Full-duplex. The failure disappeared after the switch port was changed to Half-duplex. This means that the switch port and network card speed and duplex must be the same. At present, there are many adaptive network cards and switches, according to the principle, should be able to correctly adapt to speed and duplex mode, but in fact, because of the inconsistent brand, often can not correctly achieve Full-duplex. Obviously the server network card is set to full duplex, but the switch duplex light is not bright, only manual mandatory settings to solve. Therefore, when setting the parameters of the network equipment, we must refer to the server or other workstation network equipment parameters, as far as possible to make a device matching work.