I have network functional in my freedos machines (386, 486, Athlon).

Where there's availability of packet drivers (crynwr), it is trivial.

No packet drivers makes it a lot harder, but still workable, with NDIS drivers. The linked story documents how to do it, and I've done it once before. The end result is the same packet driver interface, but backed by NDIS + a driver that acts as a proxy of sorts.

Ms-kermit is a good way to move data around with just the serial port. Once there is a working packet driver in the system, Etherdfs. It uses broadcast ethernet frames, thus does not require a TCP/IP setup.

This should all also work on ms-dos, but running that implementation is less useful today, as freedos 1.3 bumped up the compatibility considerably.

What's the compatibility with Freedos on the whole like? I assume DOS as a whole with its sheer "simplicity" means that reimplementing it isn't on the whole incredibly difficult

In general, stuff just works.

The most problematic I'm aware of is Microsoft Windows, particularly 3.11 for Workgroups. These days it works, but it still needs a patched kernel AIUI.

There are APIs in the kernel / memory manager that back then were not public (documented) and are only used by Microsoft themselves.

There is no good DOS client left to support modern implementations of SMB now that 1.0 has been removed from most modern servers. For a while I was using the MS-DOS Client with Samba, I think the new versin of Samba finally took out SMB 1.0

Samba 4.11 disabled it by default, but the code is still around as of 4.16:

* https://www.samba.org/samba/history/samba-4.16.0.html

I thought it was taken out by everyone defending against WannaCry

The page links to http://www.crynwr.com/, but the real site seems to live at http://crynwr.com/ now.

The probono page for that site has a modified date, though the index doesn't, if anyone was wondering about trying to guess the site age.

    <!-- Created: Wed Mar  3 00:26:51 EST 1999 -->
    <!-- hhmts start -->
    Last modified: Wed Mar  3 00:31:00 EST 1999
    <!-- hhmts end -->

In true hacker fashion, somebody was hacking away at that thing at half past midnight.

someone needs to set up a CNAME or a redirect.

For MSDOS (I've dabbled with FreeDOS) the MSNET client works fine with Samba (with more recent versions, I understand backward compatibility needs to be explicity turned on - same as on Windows).

It's a pretty nice way of running old 386/486 DOS boxes diskless; install a boot ROM in an NE2000/3C509/Realtek NIC, load DOS and map a network drive to the server in autoexec.bat (we use the same boxes to diskless boot old linux distros, back in the days when linux would run fine in 8Mb).