I'v got a server with 2x1Gb nics, 8 cores CPU. The nics are bonded using bonding driver with mode 803.2ad. I faced the problem with changing network cards' affinity . The irq interrupts coming from nic cards are spread to 8 cores. I tried to limit the number of irq request against 2 cores of the CPU by editing /proc/irq/devicIRQXX/smp_affinity, but it did not work for me.