Fault diagnosis method of LAN unable to access the Internet

Fault diagnosis method of LAN unable to access the Internet

A case in the book: the connection status of a computer in the LAN only sends data, while the received data packet is 0. According to the analysis of fault phenomenon, the cause of the fault may be computer fault, network cable fault, switch fault or network configuration fault. Firstly, connect the user's network cable to another normal computer for test. It is found that it can be connected. It seems that the fault comes from the computer itself. Then check the network card driver and there is no abnormality. After replacing the network card with the replacement method, the fault disappears. It seems that the network failure is caused by the network card failure. You can also follow the above step-by-step inspection to find out the cause of the fault and solve the fault as soon as possible.

Fault diagnosis method of LAN unable to access the Internet

The diagnosis method for a single computer in the LAN is as follows:

Step 1: first determine whether a single computer can't access the Internet or all computers in the LAN can't access the Internet. If a single computer can't access the Internet, in Windows

In XP / 2000 operating system, click Start / all programs / Accessories / communication / network connection to open the "network connection" window (you can also right-click the network neighborhood icon and select the "properties" command),

Step 2: then check the status of "local connection". If the icon of the local connection is that two small computers flash and the prompt "connected", it means that the line from the switch hub to the computer is normal, and the network card can basically work normally. The failure to access the Internet is caused by improper operating system settings or software restrictions. Use the ping command to Ping the remote host to see if it can ping. If it can ping, it indicates that the network connection is normal, and then check the firewall settings and proxy server settings in the computer.

Step 3: if Ping fails, it may be a network protocol configuration problem. Check the computer IP address, gateway, DNS and other configurations.

Step 4: if the local connection icon in the "network connection" window is gray, it means that the local connection (network card) is disabled. At this time, just double-click the local connection icon to re enable it.

Step 5: if the local connection icon in the "network connection" window indicates that "the local cable is pulled out", it indicates that one end of the network cable connector from the switch or hub to the user network card is loose or there is a problem with the network cable. Then check whether the network cable is in good contact. If it is in good contact, then check the network cable.

Local connection restricted or no connection

1. Local connection: start / set / network connection / click local connection / properties / general / double click "Internet Protocol (TCP / IP)" / properties / select the following IP address (for reference, you can fill it in separately):

IP address: 192.168.0.2

Subnet mask: 255.255.255.0

Default gateway: 192.168.0.1.

Use the following DNS server address preferences: 1.1.1.1

Finally, click OK.

2. Broadband connection: right click broadband connection / properties / network / select to automatically obtain IP address / OK.