9.2.4. Channel Bonding Interfaces

Red Hat Enterprise Linux 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.
To create a channel bonding interface, create a file in the /etc/sysconfig/network-scripts/ directory called ifcfg-bondN, replacing N with the number for the interface, such as 0.
The contents of the file can be identical to whatever type of interface is getting bonded, such as an Ethernet interface. The only difference is that the DEVICE directive is bondN, replacing N with the number for the interface. The NM_CONTROLLED directive can be added to prevent NetworkManager from configuring this device.
The following is a sample channel bonding configuration file:

Example 9.1. Sample ifcfg-bond0 interface configuration file

DEVICE=bond0
IPADDR=192.168.1.1
NETMASK=255.255.255.0
ONBOOT=yes
BOOTPROTO=none
USERCTL=no
NM_CONTROLLED=no
BONDING_OPTS="bonding parameters separated by spaces"

After the channel bonding interface is created, the network interfaces to be bound together must be configured by adding the MASTER and SLAVE directives to their configuration files. The configuration files for each of the channel-bonded interfaces can be nearly identical.
For example, if two Ethernet interfaces are being channel bonded, both eth0 and eth1 may look like the following example:
DEVICE=ethN
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes
USERCTL=no
NM_CONTROLLED=no
In this example, replace N with the numerical value for the interface.
Support for bonding was added to NetworkManager in Red Hat Enterprise Linux 6.3. See Section 9.2.1, “Ethernet Interfaces” for an explanation of NM_CONTROLLED and the NM_BOND_VLAN_ENABLED directive.

Put all bonding module parameters in ifcfg-bondN files

Parameters for the bonding kernel module must be specified as a space-separated list in the BONDING_OPTS="bonding parameters" directive in the ifcfg-bondN interface file. Do not specify options for the bonding device in /etc/modprobe.d/bonding.conf, or in the deprecated /etc/modprobe.conf file. For further instructions and advice on configuring the bonding module and to view the list of bonding parameters, refer to Section 28.7.2, “Using Channel Bonding”.