|   | 1 |  initial version  | 
If you do have a firewall running, it's likely to be ufw (uncomplicated firewall), the default firewall on Ubuntu. However, it shouldn't be enabled by default.
AFAIK, you can manually disable ufw by typing:
sudo ufw disable
 Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.
 
                
                Copyright Sage, 2010. Some rights reserved under creative commons license. Content on this site is licensed under a Creative Commons Attribution Share Alike 3.0 license.