Hi all!
New to Apex but not new to networking so i figured I would figure out why i couldn't use a camera on my system.
Long story short, I have a Time Warner Cable modem and behind it is a typical router/wifi setup that many of us use.
My home network was on a 10.x.x.x network and my TWC router was on a 192.x.x.x network so i had a "double router" setup that kept dynamic dns from working properly.
I never put much thought into it over the years because things just work but my kids complained about restrictive NAT issues on their xbox's

At your own risk and with some research please....
I secured the user id and password on the TWC router because it was literally admin and password to get in.
Then i set the router to be in bridging mode. This removed the 192.x.x.x network, put me at a single hop to the internet and then put the firewall burden on my internal router.

End result, my camera settings for the public ip address worked both inside and outside the house. From there dynamic dns worked properly so i was able to set up the namespace and port numbers.
Side result, my kids xbox's now work with open nat and their online games are happy. i was also able to remove a ton of port forwarding rules and let the router do its job with upnp.

Hope this helps.

Cheers,
Ron