redrumloa revealed:
Your best bet would be to buy OS3.9 which comes with a full featured TCP/IP stack. Otherwise thereare some freebies on Aminet like: http://uk.aminet.net/~aminet/dirs/aminet/comm/tcp/AmigaTCP.lha
Any of the freebies will likely be difficult to set up. Avoid Miami.
:-? Why not use Miami's excellent setup tool to configure your setup almost automatically, then copy the configuration details into another TCP/IP stack, and then use that?