[BUG] PCAP problems with Advanced NetWare 2.15c (and others)

[NCommander]

I'd like to be able to demo and create videos on ancient NetWare and Banyan VINES, but there's been a long set of ongoing issues that have made this a bit of a pain point. Some of these are from 86Box and PCem, so I'm going to list what I ran into.

1. With Advanced NetWare 2.x and NETX 2.x, the NE2000 emulation entirely bugs out and generates null packets on PCAP (Wireshark dump attached). The one IPX packet at the end was loading the ODI stack from NetWare 3.x but I couldn't get it to work either. I think this is a problem with how the NE2000 emulation is implemented, and I can reproduce this bug on PCem, so its likely been around for awhile.

The NETX client works properly under QEMU's ne2k-isa emulation, although I can't run Advanced NetWare under it to test. The attached SHGEN-2 disk has IPX.COM and NET3.COM. Use with PC-DOS 3.3 to reproduce. This should still generate frames even if a NetWare server isn't present. I can provide a pre-installed VM if needed. As the behavior is identical between Advanced NetWare 2, and the NETX shell, I suspect its the same root cause.

2. It's impossible to change VACRem's MAC address. This is mostly a problem when running multiple apps to form a network, but should be easy enough to fix. It should be noted that if this is fixed, it would probably be a smart idea to have optional MAC ranging for adapters, as I've seen some software get upset if a 3COM card for instance doesn't have the correct prefix.

3. (Unconfirmed) 86Box had revised PCAP code, that, for want of a better word, was broken. Under 86box had a very small packet queue, and if the PCAP network was bridged with a busy interface, it would constantly drop packets. This would also cause hangs quitting as 86Box would get stuck trying to disconnect an interface.

I took a brief look at the VARCem code, and it does look revised, but I don't know how much the root cause was fixed. I did manage to reproduce the hangs, but I haven't had a chance to run a comprehensive packet load test. I also am running through WINE ATM (winpcap-wine bridge), which works fine for PCem. The pull request I sent the other day was necessary to fix the description bug needed for that to work at all.

I'm primarily a YouTuber who also does archive preservation, so being able to have working PCAP in VARCem would go a very long way in documenting the early days of PC networking. @claunia pointed me at this project in my Discord, so I figured I'd get in touch to see if we can work to help fix some of these issues.

broken_pcap.pcapng.zip
SHGEN-2.img.zip