1. Step one connect your laptop to the internet via your dongle, depending on the operation system of your laptop you need to share your internet connection.
2. plug in the ethernet cable in the ps3 and the ethernet port of your laptop and your PS3 is online.
If your operation system on the laptop is Windows based
Start> go to control panel > then network (or network and sharing centre) then click on the properties tab of the connection to the internet ( a user account Control might pop up so you need to accept that) then select the sharing tab, share my internet connection) check box on. Apply. done!
you might need a re-connection or a restart.
if your operation system is Mac based
Choose Apple > System Preferences, and then click Sharing.
Select Internet Sharing.
Choose a network service from the “Share your connection from” pop-up menu, Ethernet for this case when the other end of your ethernet cable is plugged to the ps3.
Select a networking service to share your Internet connection from the “To computers using” list, AirPort for example.
If you share your Internet connection using AirPort, click AirPort Options and give your network a name and password.
if you are using a linux based operation system on your laptop then:
Start by configuring the network card that interfaces to the other computers on you network
# ifconfig ethX ip
where ethX is the network card and ip is your desired server ip address (Usually 192.168.0.1 is used)
Then configure the NAT as follows
# iptables -t nat -A POSTROUTING -o ethX -j MASQUERADE
where ethX is the network card that the Internet is coming from
# echo 1 > /proc/sys/net/ipv4/ip_forward
Install dnsmasq and ipmasq using the following command
# apt-get install dnsmasq ipmasq
Restart dnsmasq using the following command
# /etc/init.d/dnsmasq restart
Reconfigure ipmasq to start after networking has been started
# dpkg-reconfigure ipmasq
Start by configuring the network card that interfaces to the other computers on you network
# ifconfig ethX ip
where ethX is the network card and ip is your desired server ip address (Usually 192.168.0.1 is used)
Then configure the NAT as follows
# iptables -t nat -A POSTROUTING -o ethX -j MASQUERADE
where ethX is the network card that the Internet is coming from
# echo 1 > /proc/sys/net/ipv4/ip_forward
Add the line “net.ipv4.ip_forward = 1″ to /etc/sysctl.conf
# gedit /etc/sysctl.conf
Reboot your system is optional.
I hope this helps.
Respekt!