From: "Ulrik Lunddahl (PROconsult)" <ul at proconsult dot dk>
> I use the PC images in standard rack mount PC's
> This time i used Intel Gigabit adapters (PWLA8391GT), but i noticed
> dropouts more specific it looked like the adapters resets itself, because
> switch lost link for a sec or two, and then the connection was good again.
> I changed NICS, cables and so on, but the problem was still there, all i
> in the console was link down and then link up again in 2-10 seconds.
> I changed to 100 Mbit intel nics (PILA8460C3), same behavior but a lot
> more in the logs.
This first thing I would look for is IRQ conflicts. Also, you might try
different PCI slots.