Linux allows binding of multiple network interfaces into a single channel/NIC using special kernel module called bonding.
The Linux bonding driver provides a method for aggregating multiple network interfaces into a single logical “bonded” interface. The behavior of the bonded interfaces depends upon the mode; generally speaking, modes provide either hot standby or load balancing services. Additionally, link integrity monitoring may be performe
Step #1: Create a Bond0 Configuration File
Red Hat Enterprise Linux (and its clone such as CentOS) stores network configuration in /etc/sysconfig/network-scripts/ directory. First, you need to create a bond0 config file as follows:
# vi /etc/sysconfig/network-scripts/ifcfg-bond0
Append the following linest:
DEVICE=bond0 IPADDR=192.168.1.20 NETWORK=192.168.1.0 NETMASK=255.255.255.0 USERCTL=no BOOTPROTO=none ONBOOT=yes
You need to replace IP address with your actual setup. Save and close the file.
Step #2: Modify eth0 and eth1 config files
Open both configuration using a text editor such as vi/vim, and make sure file read as follows for eth0 interface
# vi /etc/sysconfig/network-scripts/ifcfg-eth0
Modify/append directive as follows:
DEVICE=eth0 USERCTL=no ONBOOT=yes MASTER=bond0 SLAVE=yes BOOTPROTO=none
Open eth1 configuration file using vi text editor, enter:
# vi /etc/sysconfig/network-scripts/ifcfg-eth1
Make sure file read as follows for eth1 interface:
DEVICE=eth1 USERCTL=no ONBOOT=yes MASTER=bond0 SLAVE=yes BOOTPROTO=none
Save and close the file.
Step # 3: Load bond driver/module
Make sure bonding module is loaded when the channel-bonding interface (bond0) is brought up. You need to modify kernel modules configuration file:
# vi /etc/modprobe.conf
Append following two lines:
alias bond0 bonding
options bond0 mode=balance-alb miimon=100