[KLUG Members] Firewalls and Gateways

[Robert Pfeiffer]

To the gurus:

I'm looking for some advice on setting up a fire wall. I've got the 
following hardware and want to make the setup as secure as possible.

(OS RH7.2)

Machine A)198.168.X.X 200Mhz box to become firewall and a router
Machine B)198.168.X.1 Current gateway, Samba and Desktop unit
Machine C)198.168.X.2 Win 98 - Girl friends machine.

I've done IP masq. before to get both my machine and hers to connect to 
the internet, but it was done a long time ago with insecure PPPD 
scripts.  I'd like to have MACHINE A now act as the internet link (I 
believe it would be the router) but also as a fire wall.  Does it have 
to be the network gateway? Or can I assign it 198.168.X.10 and use it in 
  that mode?

I'm not a networking expert, but am very eager to learn the proper way 
to set this up.  Any suggestions.  As I don't run DHCP I'm always able 
to re-assign IP addresses.

Thanks in advance for the help.