Network Connection Problem With Two Nics


Here’s my situation.
One of my MACs is used as an FTP server. The OS is X Panther (10.3.9).
I have two NIC; one (build-in) is connected to a fix IP DSL and is set as the primary.
The second PCI NIC is connected to the internal network with an XXX.18.175.100 IP.

However it looks like the second NIC doesn’t quite work the way I want it.
For example, I can ping it from any MAC or Windows PCs on the 175 network but not from my other one.
From XXX.18.175.25, I can ping 175.100.
175.25 can also ping my other network like XXX.18.43.54.
The same is true for XXX.18.43.54 pinging 175.25, however from 43.54 (or any other) I cannot ping 175.100 unless I move the secondary NIC to become the primary one, then my outside client are unable to connect to the FTP via the DSL.

Is there not some sort of setting in OS X that would permit both NIC to work together?

Sounds like you want to share your internet connection from your Mac (which basically turns the Mac into a router of sorts as it will be routing data from one network to the other).

Head on over to System Preferences and click on the Sharing icon. In there, look for a section that talks about sharing your internet connection (this is like Internet Connections Sharing in Windows). Once you enable this, I believe you have to specify which NIC will be the one sharing the connection.

Good luck!