Unsure if it will work in your case, but I'd try using Npcap instead of WinPcap.

UCyborg wrote on 2025-05-30, 00:25:

Unsure if it will work in your case, but I'd try using Npcap instead of WinPcap.

Yes, thanks ... I had hoped that they would be compatible with each other (I've used WinPcap (and Win10pCap) for
a long time - with several different things that needed PCAP .. and I don't want to mess which this working system
- so I'll have to set up another one to try it out)

I'm still trying to decide if it's worth it... I mostly use DosBox because not only can it boot DOS,
but it can run DOS stuff natively .. either way with valid PCAP / NE2000 packet driver support (in
fact DosBox/packet-network is the primary way I move "stuff" between my DOS systems and more
modern ones.

But it is nice to be able to test things on an XT/8088, AT/286 (and other configurations)...
at least I've got a tool to write files to/from floppy disk images ... so it's not hard test test small stuff
by writing it to a B: Drive ... network really is nice for over 360k though!

Ok, having dug out a spare system, using it's recovery DVD to put a fresh Win7PRO
on it ... I installed Npcap, but I'm not sure it working/configured:

It installed these files

1 Directory of C:\Program Files\Npcap
211/22/2022  03:25 PM               815 CheckStatus.bat
311/22/2022  03:25 PM             1,073 DiagReport.bat
411/22/2022  03:25 PM            18,078 DiagReport.ps1
511/22/2022  03:25 PM             2,513 FixInstall.bat
605/30/2025  04:29 AM            49,770 install.log
704/18/2025  07:42 PM            11,784 LICENSE
804/09/2021  12:40 AM             9,889 npcap.cat
904/09/2021  12:28 AM             8,562 npcap.inf
1004/09/2021  12:41 AM            66,008 npcap.sys
1104/09/2021  12:28 AM             2,404 npcap_wfp.inf
1204/21/2025  10:56 AM           323,448 NPFInstall.exe
1305/30/2025  04:29 AM             5,517 NPFInstall.log
1404/23/2025  01:59 PM         1,096,448 Uninstall.exe

I see no configuration tool... the .BAT files produce no visible results...

Once installed, DosBox "realnic list" shows:

1Network Interface List
2-----------------------------------
3 1. rpcap://\Device\NPF_Loopback
4    (Network adapter 'Adapter for loopback traffic capture' on local host)

I note Npcap mentions a loopback capability, but this is the ONLY interface?

DosBox itself cannot create a virtual NE2000 under ReadlNic=1
(which is what I used WinPcap for)

86box does now offer a "Pcap" option under Settings->Network->Mode,
and "Interface" allows you to select the loopback interface...

But... I cannot load a packet driver in the booted DOS (this is one of
the boot diskette images I used under DosBox - and I can access the network
there via an NE2000 packet driver - and yes, I have 86boxs "Adapter" set to
an NE2000 - and confirmed address/interrupt match)

Am I not seeing the correct (ie: non-loopback) interface?
or should this work as is?

-- And I do know the main Windows network interface is working - I can see/access other systems.

Do you have NPCAP listed and enabled under properties of the desired network adapter?

If not, can you try to install manually via Install ... button? Should be under Service, then Manufacturer->Nmap Project.

I only knew few programs that use it, DOSBox and forks, PCem, 86Box and Wireshark, all these should work fine with Npcap, though admittedly, I haven't used Windows 7 in several years and can't tell ATM if some incompatibility slipped in throughout years.

Yes! Npcap does appear and is enabled is the network adapter properties.

If I uninstall Npcap, DosBox "REALNIC LIST" shows nothing.
If I then install WinPcap, "REALNIC LIST" shows:

1Network Interface List
2-----------------------------------
3 1. rpcap://\Device\NPF_{88D7A876-8D5A-45C8-AA67-CD68DFDBC872}
4    (Network adapter 'Intel(R) 82566DM-2 Gigabit Network Connection' on local host)

Which indicates the actual type network adapter
(And DosBox virtual NE2000 works and can access network)

But when Npcap is installed, "REALNIC LIST" shows:

1Network Interface List
2-----------------------------------
3 1. rpcap://\Device\NPF_Loopback
4    (Network adapter 'Adapter for loopback traffic capture' on local host)

Which suggests some sort of special "loopback device" not the real network
adapter... NPCAP docs do say:

1* Loopback packet capture and injection: Npcap is able to see Windows
2loopback packets using the Windows Filtering Platform (WFP).
3
4Npcap supplies an interface named NPF_Loopback, with the description Adapter
5for loopback capture. Wireshark users can choose this adapter to capture
6all loopback traffic the same way as other non-loopback adapters. Packet
7injection works as well with pcap_inject().

Shouldn't there also be a "normal" interface?

Re Win7 - I happen to have a couple of SmallFormFactor Dell desktops which have
the original Dell Win7 recovery DVD - so it's dead easy for me to reinstall
Win7 - just boot the DVD and do a recovery -- fresh install with all the drivers
etc. working!

Npcap docs currently say:

1Windows platforms supported
2Npcap supports all Windows versions currently supported by Microsoft.
3Depending on Windows version, the driver may support a different NDIS
4version, which corresponds to a set of network stack features.
5
6On Windows 11, Windows Server 2022, Windows 10, Windows Server 2016, and
7Windows Server 2019, Npcap installs a NDIS 6.50 driver.
8
9On Windows 8.1, Windows 8, Windows Server 2012 R2, and Windows Server
102012, Npcap installs a NDIS 6.30 driver.
11
12On Windows 7 and Windows Server 2008 R2, Npcap installs a NDIS 6.20
13driver.
14
15Microsoft ended Extended support for Windows versions prior to Windows
1610 on January 10, 2023. Future Npcap releases may omit support for these
17operating systems, especially after Microsoft ends the pricier Extended
18Security Update support in 2024 for Server 2008 R2 and in 2026 for
19Server 2012 R2.
20
21Npcap can be installed on x86, x86-64, and ARM64. DLLs for the native
22architecture will be installed, as well as x86 DLLs for applications

This suggests to me that this current version (downloaded yesterday from
same website) still supports Win7.

Perhaps there is an older version of Npcap known to work on Win7 that I could try
to see if the problem is actually related to the current version? (otherwise something
off about my test system or Npcap installation on it)

Probably not related, but FYI: When I installed Npcap, there's a small menu
offering different editions.. I first picked the "works on most systems"
one which failed with a windows signature problem .. I then tried the
one which indicated something about "more compatible signature" which
did appear to install without errors.

Well... I downloaded and installed npcap-1.31 from the npcap archives
(I chose 1.31 because it's a few years old, and was a noticable amount smaller
than later ones - meaning "big changes" may have happened afterward)

And it worked!

Both DosBox and 86box see the real network interface and can access "raw"
packets over my network. (so now DDLINK works to put stuff on/off 86box !)

Are you an Npcap developer? This is still on a test system I don't mind making
changes to, I could easily try newer versions and figure out exactly where
the discontinuity occurs...

DaveDDS wrote on 2025-05-31, 15:06:

Probably not related, but FYI: When I installed Npcap, there's a small menu offering different editions.. I first picked the "wo […]
Show full quote

Probably not related, but FYI: When I installed Npcap, there's a small menu
offering different editions.. I first picked the "works on most systems"
one which failed with a windows signature problem .. I then tried the
one which indicated something about "more compatible signature" which
did appear to install without errors.

Does this show with latest 1.82? I have a hunch that certain Windows 7 update may be expected, perhaps SHA-2 update would get the other option working.

DaveDDS wrote on 2025-05-31, 17:05:

Are you an Npcap developer? This is still on a test system I don't mind making
changes to, I could easily try newer versions and figure out exactly where
the discontinuity occurs...

No, but I think trying latest Npcap on fully updated Windows 7 would be worth trying first. If that fails, they have the project on GitHub and may be open for assistance (issues page).

UCyborg wrote on 2025-05-31, 20:49:

re: Signature problem
Does this show with latest 1.82?

Yes, it was 1.82 pulled from the npcap site yesterday.
Also interesting, the signature problem didn't occur when installing 1.31

re: Npcap dev
No, but I think trying latest Npcap on fully updated Windows 7 would be worth trying first...

I just thought it might be nice for the devs to know exactly when (version) the Wi7+sig problems showed...
- easier to know which changes caused it.

This was on a fresh install of Win7(SP1) - there have been some small updates since SP1 (never enough for an SP2)
and given that 1.31 doesn't have the issue, I would think that behavior should continue as long as Win7
is supported...

I get it that some devs don't care about Win7 - I have no problem running older systems (I even still (rarely) run some stuff
on my Altair from 1976) - and still use DOS,XP systems a lot.

Contrary to what many people think today, there's lots of use for networking besides internet.
None of my old stuff has access to "the net" - I don't like when whole system updates for basic functionality
are forced for no other reason than "we think everyone should be constantly updating the stuff they
know has worked for many years" (rant off)

You can use the latest builds of 86box, from the 5.0 development.
Edit: I mean, it has huge changes compared to 4.2.1, still.

SA1988 wrote on 2025-06-01, 20:48:

You can use the latest builds of 86box, from the 5.0 development.
Edit: I mean, it has huge changes compared to 4.2.1, still.

Thanks, I didn't think I downloaded 4.2.1 that long ago, has it just been
updated? Any chance it might now recognize WinPcap properly?

I don't normally update things that are working as I wish.. and 4.2.1 with
Npcap 1.31 is working quite well for me right now (*) - it would be nice if
I didn't have to change the (working) packet capture on the host...

But... I still have one of my "test" systems set up with fresh Win7 install,
so I'm not to worried about "unrecoverable" things, and I will give 5.0 a try.

(*) I don't envision using 86box as a "daily driver" - normally when I need
"real DOS", I use it on one of my DOS systems, or booted under DOSBOX (much
faster etc.)

But sometimes I want to test something I'm creating on true ancient system,
DosBox doesn't replicate one terribly accurately... And having downsized a bit,
The "oldest" actual systems I have are: PentiumMMX, P3, P4, Core-2-DUO/QUAD ...
(Technically I do have an 8088 - but it's fairly limited, doesn't have
network or floppies (DOS 3.3 in ROM) - have to put stuff on/off via serial ...
not fast!)

I find with 86box I can test on an "actual" 8088, 286, 386 and it seems to be
replicated pretty accurately .. even floppy speed (though it's really an image,
it seems "floppy slow").

I can boot up an IBM AT, install a packet driver and easily move stuff from/to
a "modern" system over my network. I've not gotten a packet driver to work on
an XT yet, but as I don't expect to want to test much that far back, I can FDI
files to/from a B: image (and maybe I'll find a packet driver that works)

PS: Just looked and figured out why I got 4.2.1 - it's what offered as the latest "stable"
release... I'll check from time to time ... when 5.0 is deemed stable, I'll give it a try.