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Wireshark-dev: Re: [Wireshark-dev] Npcap 0.01 call for test about Windows loopback traffic capt

From: Tyson Key <tyson.key@xxxxxxxxx>
Date: Thu, 16 Jul 2015 11:10:49 +0100
Hi Yang,

Come to think of it, I got exactly the same BSoD error as Jim (BAD_POOL_CALLER). 

However, my configuration is different (I have a bunch of VMware interfaces, and an Atheros AR9485WB-EG WLAN adaptor, which is also semi-supported by Acrylic Wi-Fi - but BSoDs for a different reason (seems to be related to NDIS drivers, with that)), and multiple loopback adaptors were created on my machine (named "Microsoft KM-TEST Loopback Adaptor", instead of "NPCap Loopback", if memory serves correctly). 

Bizarrely, even after uninstalling NPCap, and replacing it with WinPCap, these KM-TEST adaptors still persist across reboots:
埋め込み画像 1

I assume that these are a side-effect of manually installing the .ini file, after attempting to run the set-up tool ("npfinstall -r", "npfinstall -li", and then "npfinstall -i") via a batch script with Administrator privileges.

I also found that although I could see packets containing a MAC address with the mnemonic "LOOP", I could not capture any ICMP traffic, when trying to ping 127.0.0.1, or ::1 (using both Microsoft Network Monitor, and Wireshark - the latter of which would not detect any interfaces, after reinstalling NPCap a few times, before eventually replacing it with WinPCap, until I rebooted).

If I get time, I'm going to see if I can reproduce the BSoD, and try writing down the steps involved.

Tyson.

2015-07-16 10:56 GMT+01:00 Yang Luo <hsluoyb@xxxxxxxxx>:
Hi Tyson,

Thanks for testing Npcap and I already knew what to do about the service not start issue. It would be better if you can provide the BSOD issue reproduce steps because I never encountered this. I also encountered the connection loss problem sometimes, but it happens in a random way and I still don't know how to reproduce it.

Cheers,
Yang


On Wed, Jul 15, 2015 at 7:03 PM, Tyson Key <tyson.key@xxxxxxxxx> wrote:
Hi Yang,

Thank you for looking into implementing this. Sadly, I tried your package on my Win8.1 x86-64 machine, and found that not only did the new NPF service not start after uninstalling "real" WinPCap (running the installation tool manually, with the -il, and -i options didn't seem to do anything, until rebooting), and then your new NPCap in "compatibility mode", I had problems connecting to my WLAN, after rebooting (and I also received a BSOD, at one stage whilst trying to capture on multiple interfaces).

Unfortunately, I don't know if I can reproduce these issues, or provide any logging information, this time - but if I get chance, I'll have another look.

Take care,

Tyson.

2015-07-11 10:15 GMT+01:00 Yang Luo <hsluoyb@xxxxxxxxx>:
Hi list,

In order not to diverge with WinPcap interfaces, I have made a "WinPcap Mode" for Npcap, it uses the same system32 directory to put DLLs and has the same "npf" service and driver name. So it can be directly used in Wireshark without any patch. 

Another news is that I have finished Windows loopback packet capture feature in Npcap, Npcap will install an adapter named "Npcap Loopback Adapter". And I can see the loopback traffic using Wireshark now (See the attached pic). It seems to still have problems, like the "(no response found!)" in the ICMPv6 packets (ping ::1) in the pic. I don't know why Wireshark shows like this, perhaps you guys can provide me a clue.


I have tested this version Npcap under Wireshark 1.12.6 x64, in Windows 8.1 x64 and Windows Server 2016 TP2.

Notice: You need to try it under Win7 and later, and no need to change the installation options, just click the "Next"s. Npcap installed in "WinPcap Mode" is exclusive with WinPcap, so you must uninstall WinPcap first (installer will prompt you this).

The README is:

The implementation internal about loopback traffic feature is:


Cheers,
Yang

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