The reason is your router has a built-in firewall that should be able to handle incoming traffic. As you can tell, there's not much to enable or disable the firewall on Ubuntu.

During Redhat 9's install, i specifically said to disable the firewall. Now, i installed lmule and it tells me that it can't reach port 4662. How can i find out if the firewall is turned on or off ...

Security experts are advising that a networking feature known as Universal Plug and Play be disabled on routers, printers, and cameras, after finding it makes tens of millions of Internet ...