I dont know which port to use



What should i fill in WAN Port and LAN open port? 9443?

You’ll sertainly want to map traffic on WAN port 9443 to LAN port 9443, but how you configure that will depend on the make/model of your router,
The link I provided has info on how to do port mapping for a wide range of makes and models of routers.


DONE! Port forwarding successful. Thanks a lot for the help. I was wondering if now anyone who knows my public IP and port number can control my esp?

Well, it’s your Blynk local server that’s the endpoint for that port, not the ESP. If they have the IP address and your Blynk Auth code then they’ll be able to control your Blynk project.
If that’s a potential problem then you should look as HTTPS/SSL.

I assume that if you have a dynamic IP address and are using a DDNS service, otherwise when your public IP changes you’ll lose connectivity to your server.


Yeah I have a dynamic IP address but for the sake of experimenting I used “what is my ip” and tested the project. I will probably buy a static ip/ uses DDNS for my server if I plan to permanently take it into action :blush:


I had another doubt. I wanted to know how to use virtual pins with blynk in this project so as to increase the number of channels I can control.

You should try a free NoIP.com account and set up an update client on your Blynk server.

If you want to know how to use virtual pins then just search the forum and the documentation.



  1. I am facing another problem. My project functions properly when I turn off the firewall of my server. However when I turn on the firewall and in advanced firewall settings set a new inbound rule for allowing communication on 9443 port then I am unable to login to the blynk app. It shows the error “Please check 9443 port is open in your server”

  2. What is swithstatus = 2 used for?

  3. After executing the following code, alexa app on discovering devices only shows “light one”. Light Two is not displayed there:

    light1 = new WemoSwitch(“light one”, 80, light1on, light1off);
    light2 = new WemoSwitch(“light two”, 80, light2on, light2off);