I have a linux box with a shared connection setup with Ubuntu 12.04's native internet connection sharing function.
I then have another device(PS3) plugged into the Linux box's Ethernet port in order to get internet access.
The PS3 gets internet connection fine and everything, but it's TOTALLY unaffected by iptables.
The command I'm (trying) to get working is something like this:
iptables -A INPUT -p udp --dport 6493 -m length --length 135 -j DROP
It does nothing though, and packets of that size are still able to be sent both to and from the PS3. Either I really have no clue how to use iptables or the internet sharing method I'm using is completely bypassing the firewall.
Any help is appreciated. Thanks in advance!