Npcap Loopback Adapter (Dec 2017 Win 10 Update) interfering with VPN?

usamaliberty · 15 Aug 2019

EdTittel said:

Npcap doesn't come from default Windows, it's a promiscuous capture driver "shim" (something that gets inserted into the normal Windows IP stack) for programs like Wireshark to grab IP packets from your network interface so they can be analyzed and displayed. While it may be causing problems, it's not part of Windows per se. As an experiment you could either disable it or uninstall it, and see if that fixes your problems.
HTH,
--Ed--

i am using wireshark and this Npcap adapter got in to my computer while i was installing wireshark but i don't really see the use of Npcap (with what little knowledge i have)

can you please help me understand what this Npcap is and how is it useful in wireshark

Thank you :)

EdTittel · 15 Aug 2019

Normally, the network interface only passes packets up the protocol stack if they meet certain criteria -- most importantly, being addressed to your home address ranges (MAC, IPv4 and IPv6 IP addresses, sockets for active TCP and UDP connections, and so forth). Otherwise, you "see" nothing else on the wire. Shifting into promiscuous mode means your protocol stack passes everything up the stack (and to Wireshark) for inspection and further processing. Except for protocol analysis or snooping, there's no need for NICs to pass traffic along that's not intended for the specific target PC on which it's running.

Hope that makes sense.
--Ed--