We don't need configuration in CentOS6.

alias eth0 bnx2
alias eth1 bnx2

[root@localhost ~]# ethtool -i eth0
driver: bnx2x
version: 1.52.53-4
firmware-version: bc 5.2.7 phy baa0:0105
bus-info: 0000:02:00.1

[root@localhost ~]# ethtool -i eth1
driver: tg3
version: 3.108
firmware-version: 5715s-v3.28
bus-info: 0000:07:04.0

[root@localhost ~]# modinfo bnx2x
filename:       /lib/modules/2.6.18-128.el5/updates/bnx2x.ko
cvs_version:    $Revision: #18 $
version:        1.50.13
license:        GPL
description:    Broadcom NetXtreme II BCM57710/57711/57711E Driver
author:         Eliezer Tamir
srcversion:     26B7ABD33A27B2FB0D77D7C
alias:          pci:v000014E4d00001650sv*sd*bc*sc*i*
alias:          pci:v000014E4d0000164Fsv*sd*bc*sc*i*
alias:          pci:v000014E4d0000164Esv*sd*bc*sc*i*
depends:
vermagic:       2.6.18-128.el5 SMP mod_unload gcc-4.1
parm:           disable_tpa: Disable the TPA (LRO) feature (int)
parm:           int_mode: Force interrupt mode (1 INT#x; 2 MSI) (int)
parm:           dropless_fc: Pause on exhausted host ring (int)
parm:           poll: Use polling (for debug) (int)
parm:           mrrs: Force Max Read Req Size (0..3) (for debug) (int)
parm:           debug: Default debug msglevel (int)

Check NIC Driver
# ethtool -i eth0 |grep driver
# ethtool -i eth1 |grep driver
# ethtool -i eth2 |grep driver
# ethtool -i eth3 |grep driver

# rmmod bnx2x
# rmmod tg3
# rmmod XXXXX

# /etc/init.d/network restart