Restricting Internet Ports

To restrict the range of ports used by WinHorizon from 1024-65535 to a chosen range, in this example 5000-6000, follow these steps:

  1. Add the Internet key under: HKEY_LOCAL_MACHINE\Software\Microsoft\Rpc

  2. Under the Internet key (HKEY_LOCAL_MACHINE\Software\Microsoft\Rpc\Internet), add the values "Ports" (MULTI_SZ), "PortsInternetAvailable" (REG_SZ), and "UseInternetPorts" (REG_SZ).
    For example, the new registry key appears as follows:

    1. Ports: REG_MULTI_SZ: 5000-6000

    2. PortsInternetAvailable: REG_SZ: Y

    3. UseInternetPorts: REG_SZ: Y

  3. Set "Use Internet Ports" to "YES" in WinHorizon and save the configuration

  4. Restart the server. All applications (including WinHorizon) that use RPC dynamic port allocation use ports 5000 through 6000, inclusive.