Problem records using nps intranet penetration

Achieve the goal: map the port of the local network ( accessible to the Internet ) device to the public network server

1. Data preparation

Download np s (server) and np c (client) installation packages: https://github.com/ehang-io/nps/releases

Installation package version (0.26.10 core version 0.26.0)

Supplement: Public network servers generally use x64 servers . Since my client is jetson nano, I chose the arm client for installation.

2. Operations on the public network server:

Create the nps folder, enter the folder, download the nps server, move it to the folder and install it

tar xzvf linux_amd64_server.tar.gz 
./nps install
nps start
ps -ef|grep nps # 查看进程
nps --version   # 查看版本

uninstall command
```
nps uninstall
```
Add the ports required for security group opening on the public network server (or open all 1-65535). The opening type can be UDP type , TCP type, or HTTP type.
Outbound direction : refers to this ECS instance accessing other ECS instances in the intranet or private network or resources on the public network. Inbound direction : refers to other ECS instances in the intranet or private network or resources on the public network accessing this ECS instance.

3. Use the browser to configure nps operations:

4. Client operations:

Create the nps folder, put the client compressed package into the folder, and decompress the nps client ( arm64 )
```
tar xzvf linux_arm64_client.tar.gz
./npc -server=47.113.149.105:8024 -vkey=br0auqkcoat879fs -type=tcp
```
Run the command generated above that needs to be executed on the client, port 8024 (nps default bridge port)
The web side displays online

You can directly put the startup command into rc.local. The first npc is a directory and the next npc is a command.

5. Verification is successful

I use MobaXterm for ssh connection. Fill in the user name and password to access the client. Do not fill in the server's.

You can connect to the client through ssh to the server port to prove that server 8003 and port 22 of the local LAN device are interconnected.

6. Server-side nps stops running

The web side cannot enter the server port 8080
nps will be disconnected, but it will reconnect. It seems that the server is hung up. The reason has not been found yet.
Connection refuse means that the server TCP port is not monitored, that is, the NPS side hangs up and will usually be restarted.
Connection reset by peer means that the nps server's tcp connection is abnormal and sends a reset signal to the npc, allowing the npc to close the tcp connection.
connection time out means the network is unavailable and the client cannot connect to the server.
close mux Close the multiplexer