I have a desktop that runs Debian, and I have just added two extra interfaces in order to try to make it function as a switch. I figured that this was cheaper than going out and buying a switch (managed preferrable, I'll try to make VLANS later for now I just want a working networking switch. I also want this machine to have a single IP address so I can access like a regular computer. The multiple interfaces will be used to make the switch while at the same time I want the computer to have only one IP address, I don't want things to get confusing with the different IP addresses for different interfaces, these interfaces will strictly stay at the 2nd level and only function off MAC addresses.

Well, I am sure something like that could be possible, but typically NIC's are either completely separate or teamed together, which could be interesting. Also desktops do not have the ability to recognize VLAN's, unless there is some program you can install that will interpret them, but I am not aware of one.

Just figured it out, I created a bridge and included them all together as specified in the /etc/network/interfaces file. it forwards to other computers and everything. Figuring out which NIC is which is the challenge.

Interesting. Well once you have figured it out, assuming it stays consistent, then at least you could label them. Also, if you do stumble upon a way to specify VLAN's let me know! I am curious now.

I think you're going to have to use ebtables
http://ebtables.netfilter.org/misc/e...-man.html#lbAV

Could go wild and run a virtual machine that uses a distro like a router or firewall appliance too. Then route everything through it.