Having issues configuring my Minecraft server! Need Help!

So I have a physical server that I have purchased and loaded Ubuntu on. I have the Minecraft server setup and I can connect to it myself, however the issue is getting other to connect. I have attempted the port forwarding and made multiple restarts as well as allowing exceptions through my firewall both on this PC and the Ubuntu server. Any thoughts? I use a Netgear Nighthawk X10 router and have Verizon.