Failure phenomenon: A school in the network classroom ready to go through the school's proxy server to the Internet, connect the network, found that can not access the Internet, after the examination found that the computer network classroom can access each other.
Fault analysis and elimination: According to the fault analysis, this fault may be a proxy server problem or proxy server and switch connectivity problems caused. First check the proxy server, found that proxy server can not access the Internet, and then check the proxy server's extranet connection, the connection is normal, and the network network cable received laptop test, you can surf the Internet, it appears to be a proxy server problem, and then carefully check the proxy server, found that the proxy server in the external network network card, and the internal network cable to the external network card. Replace the test after it, troubleshooting.
Small series recommended: LAN Some computers can surf the internet and the failure to troubleshoot cases