【 Weak current College 】 solve network problems can not be normal transmission

LAN in the long run, there all kinds of strange network failures, which makes us feel a headache should be network transmission speed "reach", or even slow to cannot access network content level, because along with the rapid development of information technology, many units and staff are unable to leave the network. Once the unit network transfer rate shake shaky or even normal transmission, then the units or employees of most of the work may not function properly. In order to improve the units or employees in the Office, trying to keep the network free so it is very important. Now, this article from the practical point of view, the contribution to the friends a few network cannot normally transfer causes and responses, I hope everyone will encounter similar network failure can be inspiring.

Real 1: DNS forwarding incorrectly thrown transport dead loop

Xiao Wang LAN recently from units of one workstation to access Internet network, discovery Web page content is displayed very slowly, but occasionally also appear unable to open Web pages.

At first he thought it was their own workstation system is infected with a virus, but ask other colleagues, he found himself with a subnet other workstations to access the external network is very slow when speed, this indicates that the fault and the possibility of the virus is not very big. Subsequently, the comparative check carefully from Kevin for a few sets of Internet speed unhappy workstation configuration parameter, see the DNS server address parameter is different, some are using units primary DNS server address, use the alternate DNS server address, logically LAN two DNS servers should not fail at the same time. Xiao Wang is a bit worried about, quickly on the LAN two servers DNS server configuration parameters are checked, check the results for its deep accidents, two DNS servers are enabled, DNS forwarding, however when setting up a forwarding address, Xiao Wang saw the IP address is 10.176.6.10 of the DNS server will resolve tasks forwarded to 10.176.6.11 servers, and IP addresses for the DNS server but 10.176.6.11 resolves task also forwarded to 10.176.6.10 Server, so when the primary DNS server cannot complete the ordinary workstation sent by parsing the request, it will be automatically resolved tasks forwarded to LAN backup DNS server, and when units of two DNS servers work status is not normally so LAN transmission channels will form a loop, it won't be long network transmission channel is blocked. Find the cause of the malfunction, Xiao Wang immediately one DNS server forwarding address set cost ISP's DNS server address, DNS resolution task would not have occurred had an endless loop; revise the DNS forwarding address, John once again test for the Internet, and this time he discovered network access has been restored to normal.

Combat 2: network virus attacks, raised channel blocking

Because of the work required, Xiao Wang prepared through their own workstation network places window to access the members of a shared file, but in this capacity not exceeding 10KB text file onto the local hard disk, he finds the network transmission speed is abnormally slow, waited for more than half an hour to complete the file transfer. Xiao Wang's first impression is their workstations or LAN was subjected to network virus attacks. At present the network there are different types of viruses, worms and viruses on the network of the most powerful destructive, it often will make full use of system vulnerability propagates replication while also using the Internet Protocol itself vulnerabilities in network transmission channel proliferation, illegal dissemination will eventually lead to clogging the network transmission channel.

In order to verify their own workstation system is already infected by a worm, Xiao Wang immediately professional analysis tools download Sniffer, use this tool from the connection state will soon know the local area network a workstation system has been infected by a worm virus; of course, if you use the Sniffer tools are not familiar with, or in their own workstation system installation tool such as Skynet firewall, and then follow the default parameters enable the professional firewall, LAN if workstation infected the worm will not send stop to network virus information, Skynet firewall can block these information sources, then view the interception results of IP address information to accurately locate the worm sources.

Find the worm trouble immediately after the workstation, Xiao Wang came to the scene of the crash, the requirements that a workstation computer workstation users temporarily disconnected from the network and restart the system, and also set the system switch to secure mode status, after using professional anti-virus software for virus killing operations. In the virus killing the operation is finished, the fault workstation is connected to the network again, this time from Kevin found Sniffer tool crawl down information and no exception, and then attempt to share access to transport, that capacity does not exceed 10KB text file will soon be the transfer is complete, it is clear in the network virus is cleared after the network transmission channel is open.

Here need to remind you that now many worms a lot of new varieties, sometimes installed on the local system of anti-virus software but not these variants of the worm, this time we can under the name of the variant of the worm to downloading professional worm killing tools. In order to prevent the worm again attacking his workstation system or a local network, you should also to Microsoft's official website to find out whether it is for the corresponding worm patches, if any, must promptly to download installation in order to strengthen the local system or network security "immunity".
Combat 3: cable connection error, caused network loops

Units each Office has its own intranet, Intranet workstation through the core switch and external network connections.Recently, a colleague Xiao Wang to your network administrator, they reflected the offices of the workstation when you access the external network is not working properly, sometimes can open Web pages, but time is not long and cannot display the Web page content, but then over time, the same Web content they can access, and will continue to have the same symptoms.

From the symptom, Xiao Wang thought may be the work of the State of network devices, or network connection is not stable; however, at the made investigation of these factors, the Xiao Wang and didn't find any problems, in order to secure, Xiao Wang will switch equipment and units of router device restart, to remove these devices the hidden system failure exists, but the fault doesn't disappear. Is it possible to switch the connection port is causing the problem?, thought it

Xiao Wang intentionally connects its indoor network master switch port a, and then do testing is not enough, in fact the core of the new switch is enabled in the port State is normal, this means it can not be normal indoor network access to the network and the core switch or not, having regard to the other branches of the internal network can access the contents of the external network, so that the fault is certainly Xiao Wang is determined by the Department of the Interior network.

Arrived at the crash site, Xiao Wang in the network to see the branches to a total of six workstations, they passed a 16 port switch and units of core switch; ask the Department colleagues often anti-virus, the answer is they often killing the virus, you can ensure that the internal network without network. Eliminates viruses, Xiao Wang will look to the 16-port switch, he saw a connection to the switch network cable mess on the floor, so he decided to be messy cable straighten out of order; at the finishing line cable, John discovered that there is a cable of two crystal head while connected to the switch two ports, it is clear that there is a network intranet, no wonder the loop inside the network workstation can sometimes occur when the Internet opens the page sometimes cannot open a Web page, this is a data packet loss serious results. Will network loop phenomenon ruled out, Xiao Wang restart at the 16 port switch and found the offices of all workstations can now open a Web page, and the contents of a Web page display speed.

Combat 4: limited concurrent connections, raised cannot connect

In order to facilitate the exchange of staff members share information, network administrators Xiao Wang specially in the server's hard disk has opened up a shared folder so that to make the employees feel free to upload and publish your shared information. However, recently, there have been several employees at the same time to reflect their Xiao shared information cannot upload to the server specified in the shared folder. Hear lot of people at the same time reflect the faulty, Xiao Wang subconsciously think that definitely is a problem with the server system; so he and two of the three-step by step, arrived at the server site, but in the site server system running from Kevin see everything is normal, then asked about the other part of the staff, that they are able to transmit to the server as you normally do share the information. On the basis of this phenomenon, Xiao Wang is of the opinion that the fault is certainly part of Workstation systems itself issues arise, such as the Internet is set incorrectly, the system is infected, but on some workstations in all possible factors examined, Xiao Wang and didn't find anything suspicious, it seems the problem or the server side. Return to the server field, open the system of Xiao Wang Computer Management window, from the window of the "shared folders" in the session list, he saw this moment should have 30 user connections on the server; take into account when setting up a server in order to reduce the burden of running the system, Xiao Wang LAN workstation specifically for units less than 80 sets the number of status, the server system, the number of concurrent connections is limited to 30, but by default each user connection even in the absence of any action to wait until 30 minutes before you disconnect from the server side, in its sole discretion. Obviously, subsequent users are unable to access the shared folder on the server, is due to the simultaneous access to the number of connections that the server has exceeded the specified numerical system; to find the cause of the failure, then the fault address up would not bother.

Xiao Wang immediately locate the server in the specified shared folder, open the folder's Properties window, enter shared label settings page, in the page number of the user connection is set up as a higher number. Considering the unit number of workstations in the LAN is not more than 80 single, Xiao Wang here will be concurrent connections value adjustments to 80, then other users in the LAN can access the server at the specified shared folder, and of course also free to quickly publish information sharing.

Combat 5: the gateway settings incorrectly thrown forward error

An organization formed a contains dozens of small local area networks, workstations, servers, install WindowsServer2003 system, responsible for the day-to-day management of the network and with the competent departments of the business relationship. Later, because the work required, the unit applications installed ADSL broadband, LAN Server host as the outside line connected hosts other workstation through a server shared outside line connections to the Internet. After the installation is configured, in addition to the server system to be able to access the external network, the other stations will not be able to surf the Internet. Carefully the Internet parameters to check and found no errors, and LAN internal workstation can access between each other.

After careful analysis, suspected problems with the server parameter, the connection to the internal network adapter address 10.176.0.1, and other workstation is in the same subnet as the other stations in the gateway address are set to the 10.176.0.1, logically, this setting is correct, this all workstations in the LAN should be able to achieve sharing access, but true.

Holding the attempt to set the server connection in the network adapter IP address 192.168.0.1, adapted to the local area network in itsHis workstation's IP address is changed to 192.168.0.XXX, gateway address all the modifications to 192.168.0.1, when completing these parameters change operation, the miracle has appeared, all workstations in the LAN shared Internet success. Obviously, this is the network access of the fault is due to the gateway is set incorrectly, causing the Internet data forwarding errors.