Simply put, port mapping, nat, and intranet penetration all mean the same thing. The same purpose is to solve cross-network problems, and it also involves network address translation. If you want to issue external network access to the intranet server, you will use one of them Way.
Specifically, port mapping, nat, and intranet penetration are different. The English name of port mapping is nat, that is, port mapping and nat are synonyms, and generally refer to the conversion of one address port into another address port, not limited to internal and external networks address. If a computer on the intranet wants to access the Internet to open services or receive data, port mapping is required.
Port mapping is divided into dynamic and static. The following uses an example to introduce dynamic port mapping. For example, if a computer in the intranet wants to access Tencent.com, it will send a data packet to the nat gateway. The data packet includes the IP and port of the other party's Tencent.com and the local IP and port. The nat gateway will replace the local IP and port with Its own public network IP, an unused port, and will record this mapping relationship for future use of forwarding data packets. Then send the data to Tencent. After receiving the data, Tencent responds, sends the data to the unused port of the nat gateway, and then the nat gateway forwards the data to the computer in the intranet to realize intranet and Public network communication. When the connection is closed, the nat gateway will release the port allocated to this connection so that future connections can continue to be used. Dynamic port mapping is actually the way nat gateways work.
Static port mapping: It is to open a fixed port on the nat gateway, and then set the data received by this port to be forwarded to which IP and port on the intranet, no matter whether there is a connection or not, this mapping relationship will always exist. You can let the public network actively access a computer on the intranet.
What is intranet penetration? Internal network penetration generally refers to internal network mapping, and internal network ports are mapped to external networks. It can be said that the definition of port mapping in the intranet and intranet interworking scenarios. There are generally two ways to implement it, one is hardware such as a public network router port external network (requires a public network IP), and the other is software that maps the external network locally (maps the external network when you can access the Internet).
The router itself has the function of port mapping. On the premise of having a public network IP, it can be used to access the internal network from the external network. For the intranet IP environment, with the help of three-party intranet mapping software, such as Quick Resolution, their principle is basically to map the intranet IP address to the external network domain name address for access.
We can install the fast resolution intranet penetration software, and when adding mappings on the software, click on the client [Analysis Environment] - [Intranet penetration mode], then jump to the internal network mapping page of the fast resolution management, you can directly Add and map the domain name in the webpage, even if the server is not on site, it can also be managed remotely. Configure the relevant information of the internal network device to be accessed, and select the domain name used to access the mapping from the external network. When the mapping diagnostic information indicates that the connection is successful, intranet penetration can be realized.
Utilizing the internal network penetration technology of Quick Resolution, devices on the external network can smoothly communicate with intranet devices through the channel built by the Quick Resolution server by accessing a fixed domain name.