Intranet penetration refers to the exposure of software services in the Intranet to WAN users through network agents. Intranet penetration can be achieved in many ways, such as firewall hardware, network penetration software to achieve. This paper mainly introduces typical Intranet penetration through NPS software.

For example, when we encounter third-party services such as WeChat/Alipay payment in our normal development process, we request the payment interface of WeChat/Alipay. The official of WeChat/Alipay needs to give us a response to indicate whether the payment is successful or not. At this time, we need to request the interface address exposed on the public network. We can use FRP as an Intranet penetration tool, so that we can locally receive WeChat or Alipay back to us requests, is still very practical.