SynAttackProtect
Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2
HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
| Data type | Range | Default value |
|---|---|---|
REG_DWORD |
0 | 1 |
0 |
Specifies whether the SYN flooding attack protection feature of TCP/IP is enabled. SYN flooding attack protection is enabled when the value of this entry is 1 and the value of the TcpMaxConnectResponseRetransmissions entry is at least 2 (see note below).
The SYN flooding attack protection feature of TCP detects symptoms of denial-of-service attacks (also known as SYN flooding), and it responds by reducing the time that the server spends on connection requests that it cannot acknowledge.
| Value | Meaning |
|---|---|
0 |
SYN flooding attack protection is not enabled. |
1 |
SYN flooding attack protection is enabled. |
Notes
This value is used only when the number of SYN-ACK retransmissions is likely to impair the server, that is, when the value of the TcpMaxConnectResponseRetransmissions entry is at least 2.
Windows Server 2003 does not add this entry to the registry. You can add it by using the registry editor Regedit.exe.