What about using a Linux /Windows PC with SLIP - Ethernet connection/router and SLIP.
Other methods: PLIP, PARNET etc.
From Amiga Networking FAQ:
SLIP allows your computer to run TCP/IP over the serial port. This allows your computer to have a TCP/IP address. TCP/IP applications such as FTP can now use
TCP/IP to deliver packets directly to your address. An analogy would be instead of having to go to the post office to get your mail, you now have a mailbox to
which the postman can deliver your mail. In more technical terms you are no longer a terminal; you have become a node.
SLIP is a "data link" protocol. It sits between the serial port and the IP stack. It pretty much takes the packets from IP, adds a wrapper to them, and sends them
out the serial port. It also takes packets from the serial port, unwraps them, and passes them up to IP. SLIP has several problems, including the fact that it is
designed entirely for TCP-IP, and is therefore of limited use for other protocols. Too many people ask for "SLIP" when they really want "TCP/IP" with a SLIP driver. You have to have both. Just like a terminal program is of little use
without a serial.device driver.
SLIP is not a full protocol. It fits in one of the layers between hardware and the TCP/IP protocol. It acts more like a device driver. It also acts like a protocol
because it has to be at both ends of the physical link, but it must have the TCP/IP protocol in order to talk to the applciations.
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Parallel cable
If the computers are close together (6 to 12 feet), then a special parallel cable can be used to connect them.
PARnet is available for PC's and can be made to work with the Amiga version.
Link It! is a commercial solution that will work with either serial or parallel,
and comes with a parallel cable.
PLIP
There is a program on Aminet called PC2Amiga.