1, the router has a port problem. You can try to change the available port. The landlord is a clever man, so I guess he has tried. )

2, router problem 2 router configuration, check the router configuration. Or initialization and reconfiguration.

3, network provider restrictions.

4, check the network cable, there is a special line table, you can check whether there is a problem with the network cable. I believe there is nothing wrong with the network cable, because the landlord said that several cables have been changed.

5, computer problems, a network card, change a usable network card.

6, computer problems 2 LSP, repair system LSP, many system maintenance tools, such as 360 security guards have initialization function.

7, computer problems three drivers, uninstall the network card driver, and then restart, let the system automatically install the network card driver. (The low version of the system is invalid, and the system that is excessively slimming is also invalid. )

8, computer problems 4 firewall, turn off the firewall, or turn off the firewall's restrictions on network connection.