Unable to control Yun outside my private network

Projects Networking, Protocols, and Devices
1

hi Guys, I'm planning to replace my Uno + ethernet shield setup with Yun, but I can't make my REST commands to work when I am using public IP. Everything are working just fine locally. With Uno + ethernet shied I was able to use port forwarding to control it from outside my private network using http "public IP:port/command". I would appreciate any advice or suggestions. Thanks in advance.

Here's my network setup: main router(wan: 218.xxx.xx.xxx; lan: 192.168.0.1)<-->second router(wan: 192.168.0.22; lan: 192.168.1.1)<-->Yun(192.168.1.103).

2

Dynamic IP services like no-ip.com and others are often used for outside connections.