[NCLUG] Firewall question

[Marcio Luis Teixeira]

Hi,

I was wanting to have some moderate degree of protection for my home network, 
but I didn't want to have a whole machine dedicated to firewall. So I decided 
to set up a single machine with two NICs. The idea was that one NIC would 
only connect to my cable modem, and have IP filtering enabled to allow only 
outgoing connections, and the other NIC would connect to my internal network.

Half of what I want to do is working -- from the external network I can't see 
any of the machines in my internal network. The problem arises when I try to 
run some daemon, such as "telnetd", on the "firewall" machine. The problem is 
that it accepts network connections on *both* NICs, whereas I would like it 
to only operate on the internal NIC. This seems like it should be easy thing 
to do, but so far I haven't found any clues as to how to accomplish it.

Is it possible to disable services on one NIC but not on another?

Marcio Luis Teixeira