Need help setting up my server. so i already got my ddns and domain. after dns redirection to my ddns, i tested my domain outside and inside of local network and i got my router page instead. i have set up port forwarding port 80 to my server ip. but it's not working.

@gashadokuro what is dnz?

Don't use NAT for this purpose. Get a direct internet connection instead (passthrough).. and for the love of God, use a static IP! DDNS is a thing, but it's not a replacement for a proper static server IP! DNS changes can take weeks to propagate in developing countries, which DDNS can't deal with. DDNS is essentially something that's built for home users that don't want to invest in a proper internet-facing server (with static public IP), and want more robustness and maintainability than a hosts file, but of which the devices will be able to resolve the DNS settings frequently enough to stay up-to-date with the changing IP at home. It's a janky setup that isn't business-grade essentially.

Also if you're going to go with a direct internet connection or let your local network face the internet in any way, you should isolate it from the rest of the network, i.e. put your server machine (VM or physical) in a DMZ (demilitarized zone i.e. a separate network of its own). The internet-facing server should not be able to talk to the rest of the network.

Personally I'd recommend getting a VPS. They're surprisingly good for their price! I'm using Aruba Cloud here which rents VPS's for as little as €1.21/month. Never had any issues with their services either, no downtime to speak of. My nixmagic.com mailers have been placed there, and by putting 2 of them in tandem (so that I can reboot them periodically without service downtime) and for the rest of it relying on the reliability of their host systems, I've been able to achieve a 100% uptime last year. Quite impressive for a budget hoster!

I would second having the prod server on an external network, pretty much all of condors advice is spot on. Dmz could be used, but dmz has its own problems. NAT is.... Ugh. Also (only skim read previous posts) if your accessing your external domain locally you may have to set up status routes to stop router from throwing u back to webgui