CentOS 6 Channel Bonding allows administrators to bind multiple network interfaces together into a single channel using the bonding kernel module and a special network interface called a channel bonding interface. Channel bonding enables two or more network interfaces to act as one, simultaneously increasing the bandwidth and providing redundancy.

CentOS 6 Channel Bonding Channel bonding (also known as “Ethernet bonding”) is a computer networking arrangement in which two or more network interfaces on a host computer are combined for redundancy or increased throughput.

mode=0 (Balance-rr) – This mode provides load balancing and fault tolerance.
mode=1 (active-backup) – This mode provides fault tolerance.
mode=2 (balance-xor) – This mode provides load balancing and fault tolerance.
mode=3 (broadcast) – This mode provides fault tolerance.
mode=4 (802.3ad) – This mode provides load balancing and fault tolerance.
mode=5 (balance-tlb) – Prerequisite: Ethtool support in the base drivers for retrieving the speed of each slave.
mode=6 (balance-alb) – Prerequisite: Ethtool support in the base drivers for retrieving the speed of each slave.

Note: Always append extra configuration in case of a rollback.

Configuring Channel Bonding

# cd /etc/sysconfig/network-scripts/
# vi ifcfg-bond0

We’ll be using mode=6 (balance-alb)

DEVICE=bond0
USERCTL=no
BOOTPROTO=none
ONBOOT=yes
IPADDR=10.0.0.10
NETMASK=255.255.0.0
NETWORK=10.0.0.0
BONDING_OPTS="miimon=100 mode=balance-alb"
TYPE=Unknown
IPV6INIT=no

# vi ifcfg-eth0

DEVICE=eth0
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes
USERCTL=no

# vi ifcfg-eth1

DEVICE=eth1
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes
USERCTL=no

# vi ifcfg-eth2

DEVICE=eth2
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes
USERCTL=no

Due to the fact that /etc/modprobe.conf has been deprecated in CentOS 6, the process of bonding network interfaces has changed a bit.

Now instead of defining your bond in your /etc/modprobe.conf, you define it in /etc/modprobe.d/bonding.conf

# vi /etc/modprobe.d/bonding.conf

Append the following onto the end out your modprobe config file

alias bond0 bonding

# servive network restart

http://www.how2centos.com/centos-6-channel-bonding/