I've created a server using IOCP mechanism to handle a thousand of Clients Socket.

So i Stress the server with 2000 connection, i send data to the server every 1 second, length of packet is 2048 bytes, the server work just fine and when i close sockets on the client all sockets are closed on the server

When i stress the server using 2500 or more, Send and receive data work very well but when i close sockets on the client, i got only 2040 closed Sockets on the server and the iocp will never send the notification to close the rest of sockets

for more information i use AcceptEx to accept a new connection, the same issue with accept using Select Events methods

i'm using Zero Byte Read to avoid WSANOBUFS but same issue

i hope i found some one here with the same problem as me

i test the server on windows Seven 64 bit CPU : i7 4790K RAM : 16 GO

IDE : Visual C++ 2013

Language C++

Are you sure that the client is actually making all of the connections?
Are you sure that the server is actually accepting all the connections?
Also, which version of Windows are you using? It used to be that "consumer" Windows had a limit to the maximum number of incoming connections; that may still be the case. If so, try with Windows Server.

i've disabled the Half TCP Connection on the registry

yes i'm very sure i got a notification for every new connection

for more information i use AcceptEx just to notifity me when there is a new connection and not to wait data (to avoid Denial of Service Attack)

i think it's my router can't handle more than 2100 connections because when i'm playing on localhost it's work just fine