I've done everything (portforward, turn off firewall, cry, ect.), and I could never ever host. I then figured out it wasn't my linksys router, but my 2wire modem. This tutorial will hellp you get your server up and running for those with 2wire modems and have port forwarded their router, but didn't work. Most likely it was your modem you needed to port forward and not your router.
Tutorial follows:
1. Go to your modem page. ( usually
http://gateway.2wire.net/ )
2. Press the firewall button at the top. (I dunno what your password is.)
3. Press firewall settings at the top.
4. Choose what computer you are hosting on in the drop down menu. Then click "Add a new user-defined application" towards the bottom.
5. Type what you see in the picture. Leave what's blank, blank. Press add definition when done.
6. Blockland should be in the left collum now. Left click it and click add. It should now be in the right collum. Make sure "Allow individual application(s)" is bubbled. Click done at the bottom. YOU ARE DONE!!!!
(You may have to reset you modem for changes to take effect.)
