8.2.3. 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-bond<N>, replacing <N> with the number for the interface, such as
The contents of the file can be identical to whatever type of interface that is getting bonded, such as an Ethernet interface. The only difference is that the
DEVICE= directive must be
bond<N>, replacing <N> with the number for the interface.
The following is a sample channel bonding configuration file:
DEVICE=bond0 BOOTPROTO=none ONBOOT=yes NETWORK=10.0.1.0 NETMASK=255.255.255.0 IPADDR=10.0.1.27 USERCTL=no
After the channel bonding interface is created, the network interfaces to be bound together must be configured by adding the
SLAVE= directives to their configuration files. The configuration files for each of the channel bonded interfaces can be nearly identical.
For example, if channel bonding two Ethernet interfaces, both
eth1 may look like the following example:
DEVICE=eth<N> BOOTPROTO=none ONBOOT=yes MASTER=bond0 SLAVE=yes USERCTL=no
In this example, replace <N> with the numerical value for the interface.
For a channel bonding interface to be valid, the kernel module must be loaded. To insure that the module is loaded when the channel bonding interface is brought up, add the following line to
install bond0 /sbin/modprobe bonding -o bond0
/etc/modprobe.conf is configured, and the channel bonding interface and network interfaces are configured, the
ifup command can be used to bring up the channel bonding interface.
Important aspects of the channel bonding interface are controlled through the kernel module. For more information about controlling the
bonding modules, refer to Section 22.5.2, “The Channel Bonding Module”.