Failure phenomenon: A company intranet, in the use of ADSL Internet, found that the network often dropped, but after the line, restart the modem can return to normal, and when the line off, ADSL modem LED display normal.
Fault analysis and elimination: After observation found that the server in this network with a single card to connect to the switch, ADSL modem is also connected to the switch. According to the fault analysis, it is possible that many ADSL-independent packets in the network will occupy the uplink channel of ADSL, resulting in the buffer overflow, causing the ADSL "dormancy" phenomenon. Install the dual network card on the server, then connect the ADSL modem directly to the server, and then connect the server to the switch. Then the Internet test, troubleshooting.