【 Weak current College 】 improve network speed excludes cables, ports, loops, and other obstacles

Normally, when a Web site cannot access, network connectivity test is blocked waiting for symptoms, these failures due to have clear phenomenon, we can quickly locate these phenomena, the failed node failure finding it is not very troublesome. However, there is one type of network failures in particular headache that network connection is open, but the Internet connection speed is crazy slow, what factors enable network access speed so slow? actually results in network access is slow in comparison, we only have each troubleshooting, to let the network access connection at full speed!
Excluding cable obstacles

Network access from the physical cable connection, don't think you are using out-of-connection cable, will not be any problems. In fact, approximately half of the network failures and physical cable connection, network cable production and plug connection method, and is closely related to the network transmission performance; for example, if we are using a physical connection cable, do not follow the standard and T568B T568A standard production, then the Internet signal transmission on cable in that section, it is vulnerable to external interference, use that cable Internet access, you can easily encounter network speed fast. In addition, if the network cable contact is not strong, Internet access is also experiencing intermittent symptoms.

So how can I confirm that the Internet is slow, is caused by the physical cable? very often, in order to determine if there is a problem with the network cable, we will which cable is plugged into a working state good laptop for Internet test, if test results are normal, basic to confirm that the network cable is not a problem; in fact, such a judgment is not necessarily accurate, sometimes a not in accordance with the provisions of the network cable, connected to the laptop all normal, but the connection to the normal desktop computer, start Internet speed to normal speed, then very slow, and even can not be normal Internet phenomenon, the reason for this phenomenon occurs mainly laptop comes with NIC device quality is high, and the desktop computer to install the NIC device quality significantly worse than the laptop.

Therefore, when troubleshooting a network cable barriers, we first need to make sure that the network cable must conform to standard and standard T568A and T568B do not meet production standard network cable should resolutely abandon, prevent future Internet generation recessive failure; secondly with professional tools test cable connectivity, if do not have professional test tool, you can use your laptop with a desktop computer, confirm that the network of the comprehensive test cable connectivity is functioning; third, check the network cable length is 100 m, distance from those long physical cable should be as short as possible to prevent future Internet users free to be too long cable circle around to affect the normal transmission on the Internet signal.

Exclude port barrier

Hubs, switches, routers and other devices, LAN or WAN environment in important equipment, the equipment of the port in bulk data information, very prone to a variety of symptoms, such as robustness, port, port lock is dropped down, once these unexpected important port, then the LAN will have a large number of client system is not functioning Internet access or access to the network's speed.

To do this, when there is a local area network for multiple computers at the same time, the Internet is slow when symptoms, we need to an important network device port State inspections; for example, you can login into the admin system, use the show command or display command scan, diagnostic work on each port; if it can't find the failed node, we can try to access the network, with the peak professional network management program view hubs, switches, routers, and other important ports of data traffic, the apparent anomalies in the data flow port to find out, and have been observing their status changes. If these ports data traffic has been great, it is not just a question of port bottlenecks, most likely a similar network in LAN, broadcast storm, the loop is not normal; on the contrary, if these important port data flow just access during peak periods of relatively large, and the usual flow to be able to recover to a normal state, then we will be able to identify these basic port may be the network data flow bottleneck location, at which point we should find ways to increase the port's bandwidth capacity. We can use several methods to do this, for example, can be divided into multiple VLANs, you can adjust the port settings, you can upgrade a network device, you can also install multiple network adapters, and so on, to expand bandwidth capacity size.

Exclude loop obstacles
In the network of small local area network environment, due to the relatively small Internet node, network structure is not particularly complicated, the chance of network loop phenomenon often smaller. However, the larger the network, the network structure of complex environments, often will reserve some alternate network cabling, network administrator, not a little attention to their access to the network, it may cause network loop phenomenon; Furthermore, when more than one switch or hub for stacking connection, also possible to connect a loop, this is because the switch or hub of Uplink ports are often the first Ethernet port share the same transmission channel, when we inadvertently Uplink ports and other Ethernet port is connected to the same client, it will throw loop failures. For example, leads from LAN room a network cable, connect to the second floor of 213 rooms, from 214 213 rooms connected to a room, if this time we are closed from the room of a network connection to 214 rooms, LAN House, Room 213, 214 rooms between network lines, might constitute a network circuit, then the Internet packets are being worked for send and verify operation, eventually causing overall network transmission speed is slow.

In order to avoid networkLoop phenomenon from occurring, we lay the network cable, you must develop good operating practices: each network cable must clearly label affixed, can not alternate lines of places as far as possible not to use, even with a spare cable, be sure to do it well written instructions. When network access is slow, the suspect network loop failure phenomenon, we can first look at alternate cable connection is correct, to confirm an alternate cable connections are correct, and then uses the partition, segmentation, troubleshoot step-by-step.

Exclude virus barrier

Now Internet network virus outbreak, and the dangers of madness is enormous, once encountered network in LAN after virus attacks, the entire network of Internet access speed can be significantly reduced, or even can cause paralysis fault occurs the LAN. Current LAN easily exposed to ARP viruses, poisoning after may have one or more computers do not have access to the Internet, or even a large number of computers that do not have access to the Internet.

Troubleshooting ARP virus barriers, we can use the LAN switch management functionality to quickly locate the infected computers; for example, H3C brand switch, we can enter the switch background management system that performs string command "disdia" to all of the LAN switching port scanning, the scan is finished, we can know what virtual subnet computer ARP viruses exist, while at the same time we are able to view the ARP virus infected PC card physical address, and then we can combine networking information, find specific ARP virus infection of your computer, that computer from the network, isolate, and use the latest version of anti-virus software to be comprehensive and thorough virus killing operations until the virus killing clean before it access to the LAN, believe that such a LAN network access speed can be restored to normal.

Of course, in order to avoid network virus drag Internet speed, we have a computer connected to the network before, made full safety protection work; for example, in a local area network installation hardware firewalls, anti-virus software, on the client operating system upgrade in a timely manner, to regularly install various vulnerability patches, some unnecessary ports, services, run off, and so on.

Exclude storm barriers

Some of the exclusions above, if still unable to improve network access speed, we can try on LAN network crisis phenomena, which are particularly vulnerable, for example, as long as there is network devices on a local area network hardware damage occurs, the network of crisis may occur, it often has a hidden, many people tend to ignore the existence of the phenomenon. In General, as the number of workstations in the LAN are increasing all the time, sent to the network's broadcast packets are also unceasingly increase, once the value exceeds 30% of network traffic, so Internet users can clearly feel the network transmission speed will slow down. And cause network storm the most likely cause is that the network device hardware is damaged, it will continue to send to the network in a large number of broadcast packets, causing broadcast storm phenomenon until the occurrence of complex communication paralysis.

To do this, when find LAN Internet access speed is not working properly, we can troubleshoot LAN for network devices hardware corruption. In this investigation, we can use switch management function, find the port traffic anomalies, after use of replacement equipment or replace port, then click troubleshooting methods. In General, hub, switch, NICs and other equipment most prone to the phenomenon of hardware damage.