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wireshark blocking a TCP connection, (?) why ?

asked 2022-10-01 14:53:37 +0000

fe77 gravatar image

Hi I try to debug a client server problem. My PC is connected by VPN to my company. Here is my question. I have a strange behaviour.

Without wireshark capturing, my application can connect, start to sync and then fail (what I want to invesigate) With wireshark capturing, I can see that my PC is initiating the TCP connection, we can see several retries, and then it fails. It is like if "wireshark" is preventing this TCP connection to work.

As soon as I quit wireshark, back to normal, connecting, synchronizing, failing.

Do you see any reason for this behavior on VPN ?

Lenovo laptop, quite new, windows 11.. everything is u to date.

Thanks for your help !


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answered 2022-10-02 13:59:21 +0000

Bob Jones gravatar image

Sounds as if you have a negative interaction between the capture library, npcap, and your vpn.

Does this issue sound similar?

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Hi Thanks a lot for your help. It was a fresh install of Wireshark but as you mentioned, it was due to an old version of Npcap. the update fixed the problem. Thanks a lot!


fe77 gravatar imagefe77 ( 2022-10-02 17:03:35 +0000 )edit

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Asked: 2022-10-01 14:53:37 +0000

Seen: 741 times

Last updated: Oct 02 '22