Thank you so much for this.
For what is this? How can we know what to put on the "ddnslastipINTx"?Author not me, but it work on my MT for two interfaces.
For it I change ddnslastipINT0 to ddnslastipINT1 or ddnslastipINT2 etc.
What "http/ https port"? 80 / 443?You need to add a Firewall rules:
"dst port" : Your http/https port.