TCPAllowedPorts

HKLM\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\ interface-name

Data type	Range	Default value
REG_MULTI_SZ	(Blank) | 0 | IP protocol numbers	0

Description

Specifies the TCP ports on which incoming connection requests (SYNs) are accepted on this interface when security filtering is enabled. Security filtering is enabled when the value of the EnableSecurityFilters entry is 1.

Value	Meaning
(Blank—the entry appears in the registry, but the value field contains no data)	No SYNs are accepted.
0 (or not in the registry)	All SYNs are accepted.
Specific IP protocol numbers	Only SYNs arriving on these ports are accpted.

Change method

To change the value of this entry, use Network and Dial-up Connections in Control Panel. Right-click Local Area Connection, click Properties, click Internet Protocol (TCP/IP), and then click the Properties button. On the Internet Protocol (TCP/IP) Properties page, click the Advanced button, click the Options tab, click TCP/IP filtering, click Properties, and then, just above the TCP Ports box, click Permit Only. This entry is associated with the values added to the TCP Ports list on this page.

Note

There is no defined or predictable response when the value of this entry includes a zero together with IP protocol numbers. Do not combine these values in this entry.

Related Entries

UdpAllowedPorts

RawIpAllowedProtocols