Network Interface Bonding on Linux

This an easy to implement yet very usefull feature.
For instance, we use it to provide our dedicated servers with a redundant path to the network.

This small walkthrough is based on CentOS, but I’m sure you’ll be able to implement it in other distributions to after having read it.

First of all:
Enable the module in /etc/modprobe.conf and pass the necessary parameters:

alias bond0 bonding
options bond0 mode=balance-alb miimon=100

More information about these parameters and the module can be found here:
http://sourceforge.net/project/showfiles.php?group_id=24692&package_id=146474 (project documentation)
http://surfnet.dl.sourceforge.net/sourceforge/bonding/bonding.txt (direct link)

Now you have actually created your bonding device, the only thing left now is to configure it:

Change directory to the network configuration scripts:

[root@server ~]# cd /etc/sysconfig/network-scripts/

Change the scripts for the underlying interfaces, these should be slaves to the bond:

[root@server network-scripts]# cat ifcfg-eth0
DEVICE=eth0
BOOTPROTO=static
ONBOOT=yes
TYPE=Ethernet
MASTER=bond0
SLAVE=yes
[root@server network-scripts]# cat ifcfg-eth1
DEVICE=eth1
BOOTPROTO=static
ONBOOT=yes
TYPE=Ethernet
MASTER=bond0
SLAVE=yes

Now it is time to configure the bond itself, for this example I’ve chosen a DHCP configuration:

[root@server network-scripts]# cat ifcfg-bond0
DEVICE=bond0
BOOTPROTO=dhcp
ONBOOT=yes
[root@server network-scripts]#

You can now restart the network and your bond will be active:

service network restart

Greets,

Koen