A network interface bond is a Linux kernel  feature that enables two or more network interfaces to act as one, simultaneously increasing the bandwidth and providing redundancy.

Overall creating the bond is not more than configuring a few files and loading the module using modprobe so everyone can do it.

Step 1:

Create the New Configuration File

Create a file in the following path called ifcfg-bond0. This file will be the configuration file of the bond:

[root@devops ~]vi /etc/sysconfig/network-scripts/ifcfg-bond0

The bond file will be a lot similar to a regular interface configuration file. The IP address mentioned in the file will be your current IP address and also the subnet mask. The file should look as follow:

DEVICE=bond0
IPADDR=1.2.3.4
NETMASK=255.255.255.0
BOOTPROTO=none
ONBOOT=yes

Of course you can add the rest of the lines you had in your original interface file. These are just the basic options.

Step 2:

Modify the Network Interfaces Configuration Files

Modify the configuration file of the interfaces you want in your bond.

[root@devops ~]vi /etc/sysconfig/network-scripts/ifcfg-eth0

The file should look as follows:

DEVICE=eth0
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes

Edit the second interface file. open the file of eth1:

[root@devops ~]vi /etc/sysconfig/network-scripts/ifcfg-eth1

This file will look almost the same as the previous file:

DEVICE=eth1
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes

 Step 3:

Load the Bonding Module

Edit the file /etc/modprobe.conf

[root@devops ~]vi /etc/modprobe.conf

Append the following line:

alias bond0 bonding

Now in order to load the module, enter the following command:

modprobe bonding

 Step 4:

Finishing up!

Warning! This part will shutdown the network to your server so make sure you can access your server from console. (if this is a problem for you I believe a simple reboot will also do the trick.)

Enter the following commands:

[root@devops ~]ifdown eth0
[root@devops ~]ifdown eth1
[root@devops ~]service network restart

and that’s it ! you should see your bond using

Sample output:

bond0 Link encap:Ethernet HWaddr 00:0C:29:57:61:8E
inet addr:192.168.246.130 Bcast:192.168.246.255 Mask:255.255.255.0
inet6 addr: fe80::20c:29ff:fe57:618e/64 Scope:Link
UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1
RX packets:17374 errors:0 dropped:0 overruns:0 frame:0
TX packets:16060 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1231555 (1.1 MiB) TX bytes:1622391 (1.5 MiB)