No offense intended but just by saying you did these things gives us no reassurance they are done correctly, after all if everything was done correctly then it would be working.
Lets move forward under the assumption that everything you have done IS correct for now and we'll revisit your settings if necessary.
Is the server being hosted on the machine you play on or another in your household?
Can you connect using its internal IP (192.168.xxx.yyy or something similar)?
Does your ISP provide you a modem that is separate than your router?
If your modem is a separate device then you may have to configure a second level of port forwarding for the Modem to the Router so that your router can forward to your server.
Do you encounter any errors when launching the server?
When your friend connects do you see any activity in the server console?
So you have 2 devices, a modem AND a router? If this is the case you may need to configure the forwarding on your modem to point to the address that was assigned to your router. In your router configuration there should be some place that indicates the IP the router received, that is the address you need to forward to on your modem.
Your forwarding on your router will point to your computer.
I understand the concept of port forwarding my modem to my router, but my modem is just asking for the start and end ports, not any kind of IP. I'm not sure how I can find the port of my router though.
I understand the concept of port forwarding my modem to my router, but my modem is just asking for the start and end ports, not any kind of IP. I'm not sure how I can find the port of my router though.
You need 25565 - 25565 so you do not need to port forward your modem.
Yes, I have allowed Java and the ports through the Firewall.
Yes, I have set up a static IP address that I have used to port forward.
No, I don't have an IP address set on my Minecraft server settings.
Yes, I have given my friend the correct IP to join, it is my public IP.
Yes, I have checked to see if my port is open, it is apparently not, even though I port forwarded correctly.
I am using a Cisco Linksys3000 router and I followed the instruction specifically for the router to port forward, it still says my port isn't open.
When my friend tries to connect, it tells him that his connection refused or something along the lines of that. Help is much appreciated
Lets move forward under the assumption that everything you have done IS correct for now and we'll revisit your settings if necessary.
If your modem is a separate device then you may have to configure a second level of port forwarding for the Modem to the Router so that your router can forward to your server.
2. I can connect using it's internal IP.
3. I do have a modem provided by my ISP, it is port forwarded for Minecraft as well, but I do not know how to port forward it to the router.
4. I don't get any errors when starting the server up.
5. I don't see any activity at all in the console when my friend attempts to connect to my server.
So you have 2 devices, a modem AND a router? If this is the case you may need to configure the forwarding on your modem to point to the address that was assigned to your router. In your router configuration there should be some place that indicates the IP the router received, that is the address you need to forward to on your modem.
Your forwarding on your router will point to your computer.
Internet -> Modem -> Router -> Your Computer
You need 25565 - 25565 so you do not need to port forward your modem.
Could you post screen shots of both your modem and router configurations so that we may see the situation you're dealing with?
Router: