I don’t know why the Trojan built by myself will always be blocked after a short time. It seems that port 443 has its own characteristics, so it is better not to use 443.

So how to switch to another port?

The answer is to use iptables to forward traffic, and use the following command to forward all requests from port 40000-50000 to port 443, so that we can use any port in 40000-50000 on the client to connect to the proxy server!

iptables -t nat -A PREROUTING -p tcp --dport 40000:50000 -j REDIRECT --to-ports 443

However, it should be noted that many VPS service providers need to release ports on the console before they can be used.