Connection Refused at TCP/IP Level
Guys, i have a web application running on Windows 2025. Occasionally, the application experiences bursts of over 500 simultaneous connections. Even though, the server showing less than 10% CPU utilization and about 75% of RAM still available, I am encountering "connection refused" errors. I can see Windows Performance counter TCPv4 / Connection Failures change when this happens. There is no antivirus deployed during my test, and Windows defender is off. i have seen similar issues on Windows 2019 and 2022 also. I suspected SynAttack detection, but the TCP diagnostic counters for SynAttack detection dont know any values. It appears to me that there is some Windows OS limitation that causes this issue. Does anybody encounter this situation before?
