> Or, get Internet service that includes a modem/ gateway with an Ethernet > port. This is probably the best answer in the long run.
Unless that modem/gateway is under the control of the ISP, in which case you're fundamentally inviting your ISP onto your local network, IOW into your private home. [ Tho, of course, you can probably arrange to confine that "local network" such that it's only connected to a single other machine which you do control and which you use as your own local router. ] Stefan