![]() ![]() However, Item 3 is often determined by your enterprise administrator. Items 1 and 2 can usually be controlled programmatically through the Windows Firewall API. Group Policy option “Allow UPnP” may not be disabled.The Windows Firewall may not be in shielded mode.The UPnP ports 19 must be opened on the Windows Firewall.There are a few requirements on Windows machines before being able to use the NAT API provided by Windows: As it is packaged as a component library, it is accessible to C/C++ and. According to the MSDN documentation, this API has been present in Windows since Windows XP. This library is contained in a DLL named hnetcfg.dll and is usually located in the \windows\system32 folder. Interestingly, I found that Microsoft Windows supports NAT mapping through a COM component library by the name of “NATUPnP 1.0 Type Library”. To write this utility, I did not want to use custom code to parse the rather complex XML format used by UPnP to communicate with applications (why re-invent the wheel?). For the purpose of this utility, we are only interested in the port mapping aspect of UPnP. It is not restricted to mapping ports on a router or WIFI device, but is also frequently seen in many other device types. UPnP (Universal Plug and Play) is a networking protocol that is used for dynamic configuration and discovery of devices on a network. ![]() This article presents a simple console utility to query the router for current mappings, to clear out existing mappings, and to add new mappings on the router. This feature is commonly known as UPnP support in the router. Another alternative is to let the application that is listening for requests from the internet to command the router to map connections from the public IP address of the router to an internal IP address. ![]() Static port mapping, however, requires that the internal device IP address remains the same (static), and makes it necessary for the user to configure a router assuming to have knowledge of IP addresses and ports. Fortunately, most routers provide some sort of port mapping, usually in the gaming and applications section of the routers configuration options. But what about situations in which a device on the internet needs to reach a device on the internal network? Without some sort of mapping mechanism, this is a difficult task. This generally works well in situations where the device initiates the request and keeps a connection open to obtain responses from the device on the internet. It is the router's job to watch which internal IP address sends a request to the internet and to then route responses to the device that originated the request. Home network routers typically use Network Address Translation (NAT) to map internal, also known as ‘private’, IP addresses to a single public IP address provided by the ISPs internet access device, such as a cable or DSL modem. In most home network environments, a router is used to provide access to multiple devices through a network connection provided by an internet service provider (ISP). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |