I recently bought a new HP Officejet 6500 printer, and although the printer is well supported under Linux by hplip, I’ve run into problems setting it up on my network. The difficulty is that Firestarter prevents the printer from being found by my computer. If I turn Firestarter off, the hplip setup program is easily able to locate the printer, but re-enabling firestarter again blocks the printer. This isn’t simply a matter of enabling the printer’s ports in Firestarter (though one also needs to do that). Rather, the underlying problem is explained in more detail here and here.
In any case, here is how to fix the problem:
1) Edit (or if necessary create) the file at /etc/firestarter/user-pre
sudo gedit /etc/firestarter/user-pre
2) Insert into this file the following two lines:
$IPT -A INPUT -p udp –dport 5353 -d 188.8.131.52 -j ACCEPT
$IPT -A OUTPUT -p udp –dport 5353 -d 184.108.40.206 -j ACCEPT
3) Save the file, exit the program and restart Firestarter. In Firestarter, enable the required printer ports if you haven’t yet. You should now be able to access your printer with Firestarter running.