Hack and / - Bond, Ethernet Bond

Configure Ethernet bonding and get a license to kill a network interface without any downtime.
For Your Files Only

The next step is to configure the bonding module with the bonding mode you want to use, along with any other options you might want to set for that module. On a Red Hat system, you will edit either /etc/modprobe.conf (for a 2.6 kernel) or /etc/modules.conf (for an older 2.4 kernel). On a Debian-based system, edit or create the /etc/modprobe.d/aliases file. In either case, add the following lines:

alias bond0 bonding
options bonding mode=1 miimon=100

The alias line will associate the bond0 network interface with the bonding module. If you intend on having multiple bonded interfaces (such as on a system with four or more NICs), you will need to add an extra alias line for bond1 or any other interfaces. The options line allows me to set my bonding mode to 1 as well as set miimon (how often the kernel will check the link state of the interface in milliseconds).

On Your Distribution's Network Service

Like with module configuration, different distributions handle network configuration quite differently, and that's true for bonded interfaces as well. So, at this point, it's best if I describe each system separately.

From Red Hat with Love

Red Hat network configuration is managed via files under /etc/sysconfig/network-scripts. Each interface has its own configuration file preceded by ifcfg-, so that the configuration for eth0 can be found in /etc/sysconfig/network-scripts/ifcfg-eth0. To configure bonding, you simply can use the basic network settings you would have for your regular interface, only now they will be found in ifcfg-bond0:


Next, each interface you want to use for bond0 needs to be configured. In my case, if I wanted to bond eth0 and eth1, I would put the following into ifcfg-eth0:


and the following into ifcfg-eth1:


Finally, type service network restart as root to restart your network service with the new bonded interface. From this point on, you can treat ifcfg-bond0 as your main configuration file for any network changes (and files like route-bond0 to configure static routes, for instance). To make this even easier for you, I've included a script for Red Hat users that automates this entire process. Run the script with the name of the bonded interface you want to use (such as bond0), follow it with the list of interfaces you want to bond, and it will set up the modules and network interfaces for you automatically based on the configuration it finds in the first interface (such as eth0) that you list. So, for instance, to set up the above configuration, I would make sure that ifcfg-eth0 had the network settings I wanted to use, and then I would run the script shown in Listing 1.


Kyle Rankin is SVP of Security and Infrastructure at Zero, the author of many books including Linux Hardening in Hostile Networks, DevOps Troubleshooting and The Official Ubuntu Server Book, and a columnist for Linux Journal. Follow him @kylerankin


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Good Article

earlan's picture

Wew, good work :D
Keep posting . . .
Hack? Are hack legal?
I think No . . .