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Application Registry Settings

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Some applications require that ports be opened dynamically to allow return traffic through the NAT. The Application registry settings allow you to set up rules that open inbound ports when outbound packets are identified for a specific port and protocol.

Note   The default registry values vary depending on which features are included in your platform. For more information, see Default Registry Settings.

The following table shows the named values for the HKEY_LOCAL_MACHINE\Comm\ConnectionSharing\Applications\<Application> registry key that you can use to configure ICS for a specific application. These values are used for dynamic port mapping.

Note   The IPNAT driver reads and configures these settings at interface bind time, as is done for static port mappings.

Value : type Description
Protocol : REG_SZ Specifies the outbound protocol that will trigger the mapping. Valid strings are TCP and UDP.
Port : DWORD Specifies the outbound port that will trigger the mapping
TcpResponseList : REG_SZ Specifies the inbound TCP ports that will open, or map back to the originating host, when the trigger is received. You can specify a range of ports, for example, 1005-1010.
UdpResponseList : REG_SZ Specifies the inbound UDP ports that will open when the trigger is received.
IsEnabled : DWORD Specifies whether this application's group of settings is enabled.

Note   After a mapping is triggered, it expires according to normal rules: in 24 hours or when the connection is closed for TCP, or in 60 seconds for UDP. The mapping is not armed again until another outbound session, or packet in the case of UDP, is seen.

Range specifiers open only one port within the range, wherever the first response is received.

The following example shows registry settings of a test application that will trigger on outbound traffic on TCP port 1000. In this example, the application expects TCP responses on port 1000, 1046, and in the range of 2000-2010, and expects UDP responses on port 999:

[HKEY_LOCAL_MACHINE\Comm\ConnectionSharing\Applications\TestApp]
    "IsEnabled"=dword:1
    "Protocol"="TCP"
    "Port"=dword:3e8
    "TcpResponseList"="1000,2000-2010, 1046"
    "UdpResponseList"="999"

See Also

Internet Connection Sharing Registry Settings

 Last updated on Thursday, April 08, 2004

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