linux computer as a network switch?

[extreme]

Hi there,
I am a complete newbie to linux. I have an old pentium-3 computer with three network cards in it. I want to install linux on it and use this pc as a network switch. Can linux be used as a network switch? if yes, then how? I am ready to install and begin with any linux distro that can support this. I appericiate your help
thnx.

[KenJackson]

I'm sure it could, but that would be quite a task. If you are the type that likes to aggressively attack a new subject and keep at until you succeed, then go for it. But I recommend you simply buy a $30 switch and then install and enjoy Linux for it's own sake. Here are points to consider.

Normally, multiple ethernet cards in one machine must be on separate, non-overlapping networks, but a switch forwards packets within the same network. That means that most of the available information and advice you are likely to find will be misleading.

I have never heard of any existing application that implements a switch. If none exists, you would either have to write one or come up with an extremely clever iptables configuration.

If you have heavy traffic and a high-speed connection, a Pentium 3 may have difficulty keeping up.

However, if you think the speed will not be a problem and you want to do this, you might consider implementing a router instead of a switch. That is, put each card on it's own network, like 192.168.1.0/24, 192.168.2.0/24, and 192.168.3.0/24, and enabling routing between them.

In that case, if you have a cable modem or dsl modem that does network address translation (NAT), then it will either have to translate all three networks, or the Linux PC will have to also do NAT to translate the other networks to the one that the modem knows about.

This could be fun, but be warned that you're biting off a lot to chew. You might want to just enjoy Linux for a while until your experience grows.