On the Solution of LAN mutual access faults

Have you ever been so confused? Can only my computer be seen when I turn on "network neighbor? Why can't someone else share resources with me but cannot access them? The NIC is good, and the network connection is normal, but it cannot be pinged to other computers ......

No one will deny it, so it is certain that your lan has access barriers. As a result, there are many possibilities for mutual access failures, and these problems are often very difficult, next we will list different barriers to mutual access and demonstrate countermeasures.

1. "It's all about Nic !"

Fault description: a NIC integrated with the motherboard can automatically install the driver in Windows XP.ProgramThe Network Protocol and related parameters have been correctly configured, but the network is disconnected during use.

Solution: first we must ensure that the NIC Driver is correct, it is best to use the driver provided by the NIC vendor, or according to the NIC model to the driver home (http://www.mydrivers.com) and other websites to download the corresponding driver. If no driver is found for the NIC, you can download the driver from the factory Website Based on the main chip model on the NIC to try the installation.

After the NIC driver is installed, you should be able to see the currently installed Nic under "Device Manager". If there is a yellow exclamation mark in front of the NIC, it indicates that the NIC has been installed, however, there is a conflict with other hardware. At this time, there are two solutions: one is to delete or temporarily disable another device that conflicts with the network card (take the sound card as an example), and then restart the computer to try to solve the problem. If yes, reload the sound card driver or change the interrupt Number of the sound card so that the two do not conflict. The other method is to delete the driver of the NIC and reinstall it. If necessary, adjust the interrupt number occupied by the NIC, until the conflict does not occur.

If a resource conflict exists, the "conflicting devices" in the "resource" tab will show the devices that conflict with the network card, the conflicting interrupt number or the input/output address, then we need to manually allocate resources. For example, some early NICs used the interrupt address "3", which may conflict with the com2 serial port. If your com2 serial port is idle, you can disable the com2 serial port in "communication port → properties" (as shown in 1), or set "onboard UART port" to "Disable" in BIOS settings, in this way, the interrupt address "3" is used by the NIC. Some PCI NICs use the interrupt address "10", which conflicts with some graphics cards. You can set "Assign IRQ for VGA" to "Disable" in BIOS settings ", no fixed interruptions are allocated to the video card.

2. "insufficient Network Resources !"

Fault: a computer can connect to the LAN and access Shared resources normally. It is also normal to copy several MB or dozens of MB files over the network. However, once a file of hundreds of MB is copied, the prompt "insufficient Network Resources" will appear, and the "Network neighbors" will no longer be found.

Countermeasure: because the computer connection and sharing are normal, it indicates that the network connection, network protocol and software settings are correct. However, frequent Data Reading is required when copying a large number of files, this requires a relatively stable transmission environment. If there is interference in the entire network line, this stable environment will be damaged and a network fault will occur. However, network devices such as hubs, routers, and switches are not very sensitive to external interference, so the biggest interference may occur on the NIC or network cable.

For an independent PCI Nic, if the chassis structure is relatively compact, installing the NIC in the slot next to the video card, sound card and other plug-in cards may cause electromagnetic interference between these plug-in cards, this causes an error message when copying large files. The solution is to change the NIC to a slot far away from the video card or sound card.

For the network cable, we suggest you use a better shield cable to effectively prevent external electromagnetic interference. Currently, the five types of cables on the market or the cat-5e cables are basically shielded cables. In addition, we recommend that you do not place televisions, audios, and other electrical appliances near computer, network cables, hubs, and other network devices.

3. "Why not let me Ping ?"

Fault description: Two Computers A and B in the LAN can connect to computer C and use the resources, but a and B cannot Ping each other.

Countermeasure: since it can be connected to other computers, this indicates that there are no problems with network connection and network protocols. Therefore, we mainly consider software attribute settings. Because the Ping program uses the ICMP protocol, most of these failures occur when the firewall software is installed on the computer of the other party and the ICMP protocol is blocked. Therefore, you need to check the firewall software settings of the computer to see if the ICMP protocol is blocked.

In addition, after the firewall attached to the system is enabled in Windows XP SP2, it automatically shields some common network functions. For example, when the computer in the network uses the ping command to check the network connection status, the error message "request timed out" will be displayed; however, after you select "allow incoming echo requests" under the "ICMP" tab (as shown in 2), run the ping command again to obtain normal feedback.

4. "The network neighbor is missing !"

Fault description: After "Network Neighbor" is enabled, you can only view some computers, some computers in the LAN, or even your own computers.

Countermeasures: no matter whether the local computer or other computer in the network is not accessible, this is because the "file and print sharing service" is not correctly installed on a computer that cannot be viewed.

When "file and print sharing service" is installed, you can click "Install" in the Local Connection Properties window and select "service, in the network service window, select "file sharing with printer for Microsoft Network ". After that, select "file and print share" in the "network" Properties window, and then select the "allow other users to access my files" check box. After the file and print sharing services are installed, restart the computer.

In addition, if the computer workgroup settings in the LAN are incorrect, you may not be able to view it directly in a workgroup. For example, for most computers, the workgroup is set to "myoffice", but for several computers, the workgroup is set to "myoffice1 ", in this way, when you open the "myoffice" Workgroup, you cannot view the computers in the "myoffice1" workgroup. Therefore, you need to unify the workgroup name. When changing the workgroup name, right-click "my computer" and choose "properties" from the shortcut menu. In the displayed dialog box, select the "computer name" tab, click the "change" button and enter it (as shown in 3 ).