Windows 10: Strange behavior Windows 10 firewall

I have written a tcp client application which shall create a connection to a unix system. I have following strange behavior with activated firewall on windows 10: Thats what I can see in wireshark: My software on Win10 starts the TCP Connection request with a SYN. the unix system sends a SYN, ACK back My software answers with an ACK the unix system terminates with a FIN This repeats all 5 seconds and after 2-3 minutes suddenly the unix system doesnt terminate the connection but accepts it with a PSH, ACK and then the connection is ok and we can exchange data When I deactivate the firewall on windows 10 then the connection works immediately and doesn't need 2-3 minutes. can someone help me what setting in the firewall could cause this? I always thought either it blocks or it blocks not. But this looks strange to me

:)

 

Strange behavior Windows 10 firewall

I have written a tcp client application which shall create a connection to a unix system. I have following strange behavior with activated firewall on windows 10:

Thats what I can see in wireshark:
My software on Win10 starts the TCP Connection request with a SYN.
the unix system sends a SYN, ACK back
My software answers with an ACK
the unix system terminates with a FIN

This repeats all 5 seconds and after 2-3 minutes suddenly the unix system doesn’t terminate the connection but accepts it with a PSH, ACK and then the connection is ok and we can exchange data

When I deactivate the firewall on windows 10 then the connection works immediately and doesn't need 2-3 minutes.

can someone help me what setting in the firewall could cause this? I always thought either it blocks or it blocks not. But this looks strange to me

 

Registry strange behavior in HKEY_CURRENT_USER\Software\Microsoft\...

I tried to clear all contents of
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts
then set security permission to logger user name () to be clear from:

• create key
• set value

and let it inherently apply to all keys under it

But it responds with icons flickering / blinking very often
so I undo the security setting.. but while keeping on registry browsing under this key I came across:

1. The jpg filetype key and userchoice key were created
2. On userchoice key the logging user () ACL was created, and
3. It's set to DENY on SET VALUE !

Is it windows 10 behavior or an intruder's been screwing up ?
Please help me.. many thanks in advance

 

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