Limited number of nic's?

[neiroatopelcc]

Hello. In an effort to make an accursed linux distro work as I want it to (and me being a windows guy), I ran into a couple problems. One of which I haven't been able to solve.
My problem : I have a system with an onboard and 6 addin nics. Linux does correctly find them all, but the last one (eth6) won't work. It won't complain or anything, but it doesn't get a dhcp response, it doesn't see anything using tcpdump, and in general just doesn't work. I've tried replacing the nic with another, but no difference. Also tried two different versions of centos (5.2 and 5.3).

Does someone know what is limiting me to 6 lan adapters?

Research:
A collegue of mine runs a HP DL585 with 16 nics, and it works fine. But he sais that according to his knowledge a HP DL360 G3 or G4 only accepts 6, while a G2 accepts at least the 10 he has tried.

The system:
468 based Pentium 4 with 512MB DDR & 250GB sata drive on a promise controller. Onboard something or other vga chip. Older noname server originally used for surveillence.

 

[photonboy]

You have 6 ethernet NICs in a single PC case? Why?

I might be able to help if I understand better.

 

[neiroatopelcc]

It's supposed to become a router for some experimental setups.
I work at a place where we educate a variety of different students, and some of them have to play with networking - and I want to confine them to the 6 booths they have - and still be able to access the internet when needed. Thus I need a system with 7 nics. ('wan' and 6x 'lan')

Anyway, I don't think usage has any influence on a solution if there is any.