How to protect Microsoft Windows from SYN Flood attack

How to protect Microsoft Windows from SYN Flood attack

Edit the registry by adding the following keys in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\TcpIp\Parameters.

Value Name Value (REG_DWORD)
---------------- ----------------------------
SynAttackProtect 2
TcpMaxPortlovehausted 1
TcpMaxHalfOpen 500
TcpMaxHalfOpenRetried 400
TcpMaxConnectResponseRetransmissions 2
TcpMaxDataRetransmissions 2
EnablePMTUDiscovery 0
KeepAliveTime 300000 (5 minutes)
NoNameReleaseOnDemand 1


Reference: http://msdn2.microsoft.com/en-us/library/aa302363.aspx