Personal Radio Server & Port Forwarding (VideoLAN or Broadwave)

First Off, very new to OpenWRT & LuCI. I have limited experience in rooting/flashing devices, an Android Phone, a WiiU/3DS/Switch for the most part. I also have some experience in setting up a personal Minecraft Bedrock Server, as well as Asheron's Call, so im not new to Port Forwarding.

I have a Linksys MR8300 and have been working with OpenWRT OpenWrt 22.03.5 for 2 days now.

While I have Plex running on a Windows machine, the port forwarding setup required me to go into DHCP & DNS and add to the Hostnames "plex.direct" and set it to the Windows PC that was running Plex and that got it to work (from my phone via 4G). Thanks to this forum for making this fix easy to search for.

What Plex cant do is share/stream from a Line Input on my sound card, connected to an AM/FM radio. VideoLAN/VLC & BroadWave Audio Streaming Server seem like the easiest apps to do this.

While I can broadcast a mp3 stream (from the AM/FM radio) locally on the network, I cannot get it to work on my phone via 4G. Port forwarding fails to open up port 8080, 80, 88, or whatever I set it to. BroadWave has in its settings, the ability to quickly check to see if the port is open and it never is.

Both VLC and BroadWave are allowed through Windows Firewall.

Is there something I need to add to the Hostnames?

Is there something I need to install in LuCI?

What you probably need is adding a firewall rule on your router, in the FORWARD chain, so that it knows to forward e.g. port 80 to your Windows machine.

Something like this:
iptables -A FORWARD -i eth0 -o eth1 -p tcp --syn --dport 80 -m conntrack --ctstate NEW -j ACCEPT

Or straight from the Web GUI of your router

That will only allow the 1st SYN packet to reach your machine, then you'll also need the 2nd firewall rule to allow subsequent traffic in both directions

E.g:
iptables -A FORWARD -i eth1 -o eth0 -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT