User`s manual

Appendix A: Troubleshooting 17
Problem: I have connected a router to the cable modem but
now cannot access the Internet or send or receive
email.
Solution: If the cable modem worked fine when connected to
directly your computer, most likely the problem is
caused by the router’s configuration or installation.
First try shutting down and restarting each computer
connected to the router. Allow the modem time to
resynchronize with the cable system.
If that does not solve the problem, your cable service
provider may be using the cable modem’s MAC
address and the MAC address of the device that the
cable modem is plugged into. If you add a router and
connect the cable modem directly to the router’s
WAN port, you are changing the MAC address that is
being used and sent to the cable service provider. You
may need to contact your cable service provider and
give them the MAC address of the router’s WAN
port. The provider will then add this MAC address to
their approved list, and you will be able to access the
provider’s cable network using any computer
connected to that router. You may also need to check
that the DHCP client on the router’s WAN port is
enabled. If you need help, look in your router manual
or contact your router manufacturer.
Problem: When I power-up my computer, I receive the on-
screen message “Unknown Network Adapter.”
Solution: This problem can result if the Ethernet or USB
adapter hardware is physically present and recognized
by Plug -and-Play, but the proper drivers were not
installed; Windows may have added the device to the
Other Devices list under Device Manager. Uninstall
your cable modem (see page 30) and then reinstall it.