Hi, i'm new to linux

My office already has an internet connection throurg Fiber Optic. We're planning to add downlink only connection via vsat.
his is the diagram

(downlink)
vsat
|
| LAN A (downlink : vsat uplink :fo)
linux box--|-- LAN B (downlink : fo uplink : fo)
| LAN C (downlink : fo uplink : fo)
|
fo
(downlink/
uplink)

Is thera a way to make this combination?
We're curently using Red Hat 7.3 and ipchains

I could be wrong but I don't think you can. Pretty sure when you ask for something off the net (web page, whatever) it has to come back to you on the same iface.

We have two inet connections here at work and I certainly bias the traffic between the different links accordingly (for example web traffic on the fast link, mail on the slower one) but I can't send say a request for a web page out one link and exepct a reply from the other.

at least afaik.

having said that I know sat typically uses a dial up up stream connection so maybe that can be simulated across the fibre link if the isp has some way of allowing that.