What I'm trying to archieve is IPX over PPP for multiplayer games like Doom etc.

Dosbox does support IPX natively, but UniPCemu doesn't. But both support TCP-based serial line connection using their dial-up modems.

So Dosbox and UniPCemu can both dial up to the UniPCemu server version and exchange IPX packets over PPP with it, which are broadcasted across the ethernet network of the host (using the ethertype for IPX).

So Dosbox (or even UniPCemu) can then communicate with another client using the packet server running the IPX/PPP(IPX over PPP) protocol (IPv4 is already supported now).

But Windows 95 IPX I'm testing with is barely sending valid packets when IPX is busy? Both clients to the packet server are only seemingly receiving their very own packets they send on the network (according to WinDump running inside both Windows 95 clients). But the packets the server receives are broadcast IPX packets (with a broadcast IPX destination address), but the other side of both clients doesn't receive the packets?

Also Windows 95 starts sending those weird packets mentioned above (what I've written down is the format of how each packet is transferred after the server decrypts the PPP IPX packet from each of the clients). So what's written down there is what 'PPP' packets Windows 95 sends to the server. It seems to encrypt some weird headers on all IPX packets?

Just managed to get PPP IPv4 working. With the new ARP handling added, it can reach both the internal network (depending on net mask), host network(if net mask is specified correctly for that, which is seperate from the previous netmask for internal packet server clients) and internet (basically the default route). It performs ARP for all but the internal network routing, keeping 1 entry cached for it's ARP cache (basically the most recently used IP address, as a 1-entry FIFOish structure).

After the latest bugfixes and improvements (allowing network 0 when sending packets to be set to the network number that's negotiated during the IPXCP phase and implementing the IPX broadcast network number's functionality to actually broadcast accross all networks), Windows 95 seems to be able to communicate to the other Windows 95 host. Although I can't setup file sharing properly to verify it.

I'm going to try and install Doom 95 again and try multiplayer that way... Perhaps more success this time.

OK. So I configured the Windows IPX settings, made the 3rd tab of the network connection say the name of the first machine.

Then ran Doom 95 again with the "IPX connection to DOS or Mac DOOM" option. Set it to 2 players, default port (1000).

Chose new game on the first client, waited for it to get to the sync phase and then chose the second client as well.
Then both synchronized and started a multiplayer game of Doom on Windows 95 over dial-up IPX(the option says: "IPX connection to DOS or Mac DOOM")! 😁 😁 😁 😁

Multiplayer using Doom 95 with the IPX to DOS option (the second in the list) seems to work properly. Although I only tried it with 2 clients at the same time, more clients should theoretically work as well! 😁

Although Windows 9x networking with file shares seems to not work due to Windows 95 complaining about user accounts for it?

Edit: IPX seems fine now as far as I can see. MS-DOS internet using arachne over PPP seems to be working properly as well (I can even browse these forums with it now! 😁 ).
But Windows 95 internet seems to not do much atm?