does anyone have any good tips or tutorials for making slack into a router, i havent done this before with slack and don't know what i have to do to make sure that all ports are blocked from the outside unless i specify that it should be open, and what about port forwarding, how is that done, the actual routing part seems to be working as i enabled ip_forwarding in slack and it seems to work as a router

i will continue googling this but was hoping that some of you may have some nice tips or tutorials on this, so far the searching is going slow

Well, if you're used Cisco equipment, you might find Zebra useful. It provides an IOS-like user interface.

well i looked at that and it seems too complicated, i just need to know how to make it work as a NAT, forward ports to the inside, allow some ports from the outside to go to the router (such as ssh) and no firewall on the inside (all ports open by default on the lan ip, all closed by default on the wan), i've been going torough many scripts but they all seem to restrictive and firewalling the lan ports

I would say Iptables.?!!

Basically my server uses iptables to share my internet conection using NAT with client machines on my lan.
It allows bi-directional communication from any hosts within my designated lan,and silently drops all incoming packets from extenal sources,i.e the net.

You can apply filters using interfaces,ip adresses or ip subnets or tcp/udp ports and in any direction that you wish.
very flexible and powerful.
On the down side;its configuration is a bit cryptic IMO .
There is alot of docs on it n the web though.
Is this what you require?

i found what i needed, a script that can get iptables running and allow me to drop the firewall on any interface using an easy config file

http://www.asgardsrealm.net/linux/firewall/