Cause analysis:
Generally, it is related to the failure to assign the correct IP address, DNS, proxy server setting error, firewall, third-party security software, and wireless route to the internet connection interruption.
Solution:
1. For a home computer, IP addresses are automatically obtained by default. The automatically obtained IP addresses must be allocated by the DHCP server (in the home environment, wireless routers generally automatically allocate IP addresses, the default network segment is 192.168.1.X). If the DHCP server does not correctly assign an IP address to the computer for some reason, the system automatically assigns a 169 IP address to the NIC. x. x. X ). You can enter IPCONFIG/ALL at the command prompt to view the IP address obtained by the wireless network adapter.
2. If the IP address allocation is incorrect, first check whether the system's DHCP service is enabled: Start-control panel-management tools-Computer Management-services and applications-services, select the properties of the DHCP Client service to make sure the service is in the starting status. If you cannot automatically obtain the correct IP address after enabling this service, manually enter the IP address for testing or reinstall the Wireless NIC driver.
3. If the automatically obtained IP address is normal, disable the third-party firewall test.
4. Check whether any third-party security tool has added its own protocol to the network protocol, thus affecting network access. For example:
5. Clear the DNS cache test, run WIN + R, press cmd and enter ipconfig/flushdns in the command prompt. You can manually clear it.
6. Reinstall the Wireless NIC driver for testing. Click here
Go to the Lenovo official website driver download page>
7. In the LAN environment, it is recommended to check with the network administrator whether a proxy server is required.
1. Open ie, click the "Tools" menu, and select "Internet Options" from the drop-down menu ";
2. Under "Internet Options", click "LAN settings" under the "connection" tab ";
3. In LAN settings, tick "use proxy server for LAN" under the proxy server and enter the server address and port number in the address bar.
4. Click "Advanced" to set the following detailed parameters.
8. Directly plug the network cable inserted on the WAN port of the wireless router into the interface of the laptop Nic to access the Internet. If the network connection fails, we recommend that you use another computer for testing. If the other computer cannot access the internet, contact the network administrator or ISP for confirmation.