This article is from the Amiga Networking FAQ, by Richard Norman with numerous contributions by others.
Yes, Almost all Amiga models can be hooked to the ethernet. Using the serial port is the cheapest, but the fastest is a direct connect using an ethernet adapter card.
For the 1200 Interworks has an ethernet card called ICard that will support the major protocols. They also have some Amiga peer to peer software products for the ICard.
For the 500 and 1000:
The A2065 has reportedly been used successfully with third-party expansion boxes, such as Bodega Bay. It has also been reported that the A2065 card can be used with the Slingshot expansion device used with an Amiga 500 and a SupraDrive 500XP's pass-through.
The A2065 has been superseded by the Ameristar A4066 . Don't know if it works with the A500 or A1000 expansion buses.
The serial port approach for TCP/IP is supported by:
several flavors of AmigaNOS AmiTCP I-Net 225 Miami TermiteTCP
all of which require SLIP or PPP to use the serial port. DECnet and DNET can be also be used with the serial port.
 
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