1. Configure the switch
The switch port is configured as 100M full duplex, and the server is equipped with an Intell00M EISA network card. The speed becomes extremely slow when data transmission is transmitted with large traffic loads. Finally, it is found that this network card does not support full duplex. After changing the switch port to half-duplex, the fault disappears. This means that the switch ports must be consistent with the network card's speed and duplex method. Currently, there are many adaptive network cards and switches. Due to inconsistent brands, the full duplex method cannot be correctly implemented, and only manual forced settings can be solved.
2. Twisted pair wire sequence
The distance between the server and the switch is changed from 5 meters to 60 meters, but the connection cannot be connected anyway. Why? If the locations of ether, 2, 3, and 6 are not used, but the lines used by the original pair are separated, a winding will form, resulting in greater crosstalk (NEXT) and affecting network performance. The reason for the above failure is that the pairing lines of 3 and 6 are not used, and the connection cannot be connected when the distance becomes longer. After re-ordering the RJ45 head, everything will return to normal.
3. Network and hard drive
The bottleneck of the network based on file access and printing is the speed of the server hard disk, so configuring the server hard disk plays a decisive role in the performance of the network. The following are some suggestions for your reference:
·Select SCSI interface and high-speed hard disk.
·Hard disk array card can greatly improve the read and write performance and security of the hard disk, and it is recommended to choose.
·Do not allow low-speed SCSI devices (such as CDs) to share the same SCSI channel with the hard disk.
4. Network segment and traffic
On a certain server, there are two workstations that read and write files very frequently. When the server only installs one network card to form a separate network segment, all devices on this network segment react very slowly. When the server installs two network cards and forms two network segments, the two workstations that read and write files very frequently are connected to different network segments respectively, and the response speed of all devices in the network has increased significantly. This is because the increased network segments share the original concentrated data traffic, thereby increasing the network's response speed.
5. Bridge and routing
Install a set of microwave networking equipment. When debugging online, the server always prompts that the current network segment number should be the other party's network segment number. After changing the server's network segment number to the same as the other party, the server's alarm disappears. Ah! It turns out that this is a set of equipment with bridge properties. Later, a microwave networking device was installed with another location, and the products from another manufacturer were replaced, and the network segment numbers on both sides were changed to the same. However, after the device was installed, an alarm appeared on the server: the current routing error was used. After modifying the network segment on one side, the alarm disappeared. It is obvious that this is a set of routers. The characteristic of a bridge is that it is on the same network segment, while the routing must be on different network segments.
6. Broadcast interference
There is a set of application software for sending information through broadcast at both ends of the above-mentioned networking through bridge devices. When they run at the same time, both servers will issue an alarm: Incomplete packets are received. After transferring one set of application software to another network segment, the alarm disappears. This is because there is no limit on the broadcast of the network on the same network segment. The two broadcasts create mutual interference and generate alarms. After moving an application software to another network segment, it is equivalent to routing the broadcast of this network segment and the broadcast on another network segment, thereby limiting the interference of the broadcast, which is also the most important role of the router.
7. WAN and grounding
I accidentally plugged the power plug of the router into the mains socket, but the 64K DDN just couldn't connect. It was normal for people from the Telecommunications Bureau to check the circuit. Finally, they checked the grounding voltage of the router power supply. They found that something was wrong, so they switched back to the UPS socket and everything returned to normal. The grounding end of the router's power plug is broken, resulting in frequent loss of data packets, and it is sometimes good and sometimes bad when doing PING connection. Everything is fine after replacing the power cord. Because the connection of WAN involves remote lines, the grounding requirements are relatively strict, so that strong anti-interference and achieve the specified connection rate, otherwise strange failures will occur.
Article entry: csh Editor in charge: csh