This toolkit uses TCP protocol to detect NAT types.
It is divided into a server and a client, which work together to detect the specific NAT type of the client's network.
Currently, it can identify the following 5 types of NAT:
- NAT0: Public IP, no NAT
- NAT1: Full Cone NAT
- NAT2: Restricted Cone NAT
- NAT3: Port Restricted Cone NAT
- NAT4: Symmetric NAT
Note: This toolkit confirms to no RFC, the server and client must be used together.