Learning to implement a small server with the ESP8266 NODEMCU Amica board, it works and responds to a simple command by writing a string on my browser's screen. The server can be accessed from internet. I am using a noip.org Dynamic DNS service, noip.org client runs fine on my PC refreshing dynamic public IP. My router's DHCP provides IP 192.168.1.141 to the board. In my LINKSYS E900 router there is a port forwarding rule: external port 999 to local port 80 to IP address 192.168.1.141 TCP. Firewall is enabled and all ports show as closed or blocked if checked, except for port 80 and the forwarded port 999.
Using noip.org DNS like with this command: mickey.hopto.org/hello the server responds with a string "Hello".
Notice that I am not using any port number in the command line.
If I disable the rule in the router, It works fine as well !!
If the rule is enabled and the port number used in: mickey.hopto.org:999/hello , it works fine.
Changing the port number to any non forwarded port as in: mickey.hopto.org:1234/hello , the connection is refused.
Resuming: with or without a forwarding rule in the router, the following always works fine: mickey.hopto.org/hello .
If the forwarding rule exists and enabled, it works with mickey.hopto.org:999/hello
I need the server to work only if I invoke the correct port number. If SEVERAL rules pointing to different external ports and same destination local IP is the same 192.168.1.141, mickey.hopto.org/hello , works fine.
Could somebody explain how can this happen ? What am I doing wrong ? How to correct it ? I am sorry for being inexperienced in this subject.
Thank you.
