Hi there,

I have only basic knowledge in Unix but I'm eager to learn.
I have a new complex (for me) exercice and I have no idea how to start.
I have a regular network on witch I'm trying to plug another network.

Here is an image of the physical network.

• On the left is the original, three-node, standard, home network (192.168.1.0 / 255.255.255.0): An internet box (192.168.1.1), my computer (192.168.1.32) and a server (cassiopeia 192.168.1.224).
• I've added two ethernet adapters to cassiopeia.
  • One belongs to the top right network (172.16.199.0 / 255.255.255.0): a four-node network with cassiopeia (172.16.199.1) and 3 machines (172.16.199.151..153)
  • The second belongs to the bottom right network (172.16.70.0 / 255.255.255.0): a two-node network that could host more machines but I'm laking a switch.

All three networks work fine and all machines within the same network can communicate.

What I need is to set cassiopeia (a GNU/Linux Debian) to enable communication between networks:

• Set cassiopeia as gateway to the internet for 172.16.199.xxx
• Set cassiopeia as gateway to the internet for 172.16.70.1
• Set cassiopeia as a link between the two 172.16 networks

Let me give more specific needs:

• When 172.16.70.151 requests something like 172.16.199.152, it stays in the top right network
• When 172.16.70.151 requests something like 172.16.70.1, it's routed to the bottom right network
• When 172.16.70.151 requests something like Google, it's routed to the internet box
• When 172.16.70.1 requests something like 172.16.199.151, it's routed to the top right network
• When 172.16.70.1 requests something like Google, it's routed to the internet box

So far, I have set machines like this:

• address = 172.16.199.151..153
  netmask = 255.255.255.0
  gateway = 172.16.199.1
• address = 172.16.70.1
  netmask = 255.255.255.0
  gateway = 172.16.70.254

Now comes my question:
What should I install on cassiopeia (GNU/Linux Debian) to serve my needs? Is is a gateway, a router or what? Do you know free softwares? Do you know man pages to help me configure it?

Thanks for your help.
Santiago