Thank you, elch.
Code:
sudo echo 1 > /proc/sys/net/ipv4/conf/all/forwarding
was giving the permission denied error.
But I tried the following
Code:
sudo -i
echo 1 > /proc/sys/net/ipv4/conf/all/forwarding
and it worked just fine.
My firewire Internet connection sharing has stopped working. I couldn't find the reason. And I was really tired to type all the commands. I just got a router... didn't really want to waste my time onto the problem anymore.