RPCEmu Real hardware, real sharing
Discs on an emulated machine appear on a physical Acorn machine on the same network, and the other way about, as though both were real.
Networking
Machines that can see each other
Acorn Access and ShareFS are how RISC OS machines shared their discs, and they work here. Two machines on one computer find each other with nothing to set up, and from there two routes lead outwards.
To your own network
A real Risc PC in the same room joins in
A machine sits behind NAT, which normally swallows the broadcasts Access depends on to announce itself. The emulator relays them onto your real network instead.
One relay per computer
Only one emulator on a host needs to do the relaying, and the others step aside on their own. You can also say so deliberately.
An address of its own
Every machine gets an address worked out from its own hardware address, so two people who have never met can put their machines on one network without agreeing anything first.
To anywhere else
One virtual network, wherever the machines are
Point several emulators at a JSON tun/tap server and they are all on the same network. The server can sit on a Linux box while Windows and macOS machines join it over the internet.
It crosses computers
Only the machine running the server needs a tap interface, which is far easier to arrange on Linux than on the others. Everyone else just connects.
Other emulators too
RISC OS Pyromaniac speaks the same protocol, which is Charles Ferguson's, so a machine here and a Pyromaniac elsewhere can reach each other.
One place to watch it all
Every frame passes through the server, so the whole network can be traced in one place instead of per machine.
When it misbehaves
Every frame, in Wireshark
An emulated machine has no network card for a capture tool to point at, so the emulator provides the capture itself.
Straight into Wireshark
Stream the capture down a pipe and get real Wireshark, live, on a machine that has no interface to select.
A file, or a window
Write a .pcap to open later, or watch frames arrive in a window that decodes them as they come.
It names the RISC OS protocols
Freeway and ShareFS are labelled, where a general-purpose tool shows only unnamed UDP traffic on ports nobody recognises.