Do you have information on how AS225 from CBM became I-Net225 from Interworks?
Part of it may have been licensed/acquired/etc. from Commodore. The authors of "I-Net 225" (Michael B. Smith & Jim Cooper) were part of the networking group at Commodore, who developed the original "A225", "Envoy", "AS225", etc. Commodore (of course!) disbanded the group.
It's possible that both "I-Net 225" and "Envoy" became commercial products because Commodore just didn't see any sense in that Internet thing, local networks, etc.
Commodore certainly lacked the in-house resources to make anything out of the code base, so maybe (I'm speculating) the networking group members were permitted to keep their work and commercialize it.
The "ReadMe" file on the "I-Net 225" installation disk acknowledges the origin of parts of the package.
I quote:
Parts of the "I-Net 225" package were based on a TCP/IP package released by
Commodore Business Machines, Inc. The original Commodore package (AS225)
was
Copyright © 1990-1993 Commodore Business Machines, Inc.
End of quote.
I was part of the team which created the "Amiga Surfer" package at Amiga Technologies GmbH back in the winter of 1995/1996. It was built around the Amiga Internet application software available at the time, which included "I-Net 225" and, for example, Oliver Wagner's early "Voyager" browser (bless him). We didn't realize how far ahead of its time this project was when it was under development.
My part of the work concerned the dial-up connection to the Internet, which would use the infrastructure IBM had set up for OS/2. You first had to sign up for an IBM account, and then the access information would be written out as configuration files for "I-Net 225" to use. I wrote the program which sets up the modem, the serial device driver, and which performs the IBM account setup.
Once the configuration files were in place, you could go online by launching the "StartInet" program, if I remember correctly.
And can you confirm that it should be able to connect to Internet (albeit IPv4) using SANA-II ethernet device even today? 
Yes. I personally used "I-Net 225" to connect my work machine (an Amiga 3000 UX) to a different Amiga 3000 running NetBSD, with both using "Ariadne" Ethernet cards, back in 1997/1998. I did not connect this setup to the Internet because back then this required a dial-up link, rather than the much more convenient DSL gateway router setups we use today. Had a gateway router been available to connect to the Internet back then, changing the default route to use that router would have easily allowed the "I-Net 225" setup to access the Internet.
The version of "I-Net 225" which I knew did not support DHCP (or BOOTP/RARP), which means that you have to edit/create certain configuration files, knowing exactly which information to enter into them. That's a challenge all by itself.
Setting up the network, however, works differently in "I-Net 225" than in "AmiTCP" or "Miami". Configuration files are stored in "S:", and in "ENV:". The documentation explains how all the pieces need to be set up, it's just that it requires a lot of prior knowledge to put it all together.
In so many words: "I-Net 225" is much harder to set up than the Amiga TCP/IP stacks we use today, but it does get the job done, eventually, if you see it through. "I-Net 225" was the only part of the "Amiga Surfer" package which gave us no trouble at all, and that's saying something.
One more thing: the "I-Net 225" API is different from the one used by "AmiTCP" (and "Miami", "Roadshow", etc.). Back in the early days, application software would support both the "AS225R2"/"I-Net 225" API and the "AmiTCP" API, but nowadays it's unlikely that anything but the "AmiTCP" will be supported. So even if you managed to set up "I-Net 225" correctly, you might be restricted to use the shell commands and applications which ship with "I-Net 225".
