I can’t seem to portforward it so others can connect to the server from FreeNAS. I can connect locally but I am unsure which IP to give out to people who want to connect. Can someone point me in the right direction for finding that IP?
If you are able to connect locally (over LAN) you need your external IP adress. You can see this by going to the following webpage from any computer connected to your LAN: http://whatismyipaddress.com/
This is the IP adress all your external (WAN / Internet) users need to connect to your server.
After this you need to set up your gateway / router (for most users this would be your wireless router) to port forward from WAN to LAN. You do not need the external IP adress for this, only your MineOS servers LAN adress. Read more about that here: http://www.wikihow.com/Set-Up-Port-Forwarding-on-a-Router
You also need to make sure your FreeNAS is set up to accept connections from WAN adresses, not only LAN adresses.
When I go to that link to find my IP address it is giving my IPv6. Is there a way to disable this?
Try this link: http://www.myipaddress.com/show-my-ip-address/
IT may be that your ISP only provides IPv6 adresses, which would mean that you would have to contact them for this information.
That one worked for me, thanks for the help. I believe I have it correct now.