Constant server disconnects

I can't seem to play on any server, I'd just get randomly disconnected just because. I've tried watching minecraft log but no errors there; I just get "Disconnected from server". Luckily I got this error once: io.netty.channel.AbstractChannel$AnnotatedConnectException: Syscall: getsockopt(...) I have googled the error and tried all the possible fixes I found but none worked.
These are the fixes I tried:

• Reinstalling Minecraft
• Reinstalling Java
• Restarting my computer
• cmd command: ipconfig /flushdns

Forgot to mention that this happens on every version I play with. I've also tried vanilla servers and still get disconnected...