nmap / nmap/npcap

WinPcap works vs npcap gets nothing on Windows Server 2019 VM in HyperV

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Dominant language
C
Stars
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Forks
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Description

I was setting up PPTP on a Windows 2019 server environment yesterday and I wasn't sure that the firewall between the Windows box and the Internet was allowing the correct TCP and GRE traffic ((tcp port 1723) or (proto 47)). With npcap-0.9995 installed, I brought up the latest Wireshark and tried to capture traffic on all interfaces (5 interfaces) using this capture filter. Absolutely no traffic was observed. Same results were observed selecting different interfaces.

I uninstalled npcap, rebooted the box (just to be sure), installed WinPcap 4.1.3, fired up Wireshark and configured a capture with the same capture filter on the single Ethernet interface visible with WinPcap and readily captured both the TCP and GRE traffic.

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First steps

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  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the comparison on Windows Server 2019 in a Hyper-V VM with npcap-0.9995 and Wireshark, using the reported TCP 1723 and GRE capture filter. Compare captures across the five npcap interfaces with the single WinPcap Ethernet interface; done means the npcap setup captures the same traffic or the limitation is documented.

Written by the indexing model from the issue text.

Assessment

Tech stack
c
Domain
networking, operating-systems
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
25/100

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