Enabling the Layer 7 Gateway appliance to leverage channel bonding

Products

• CA API Gateway

Issue/Introduction

Channel bonding is a computer networking arrangement in which two or more network interfaces on a host computer are combined for redundancy or increased throughput. Channel bonding can be very valuable when deploying the Layer 7 Gateway in a physical hardware appliance. These appliances are pre-built with multiple Ethernet interfaces that can be leveraged via channel bonding in certain circumstances. 

Bonding a channel involves a master bonded interface configuration (bondN), and one or more slave adapter configurations (ethN). In both circumstances, N is a unique integer identifier used to differentiate multiple interfaces from one another. For example, eth0 and eth1 may be bonded into bond0.

Environment

Release:

Component:

Resolution

To create a channel bonding interface, create a file in the /etc/sysconfig/network-scripts/ directory called ifcfg-bondN, replacing N with the number for the interface.

The contents of the file can be identical to whatever type of interface is getting bonded, such as an Ethernet interface. The only difference is that the DEVICE directive is bondN, replacing N with the number for the interface used above.

An example bonded interface configuration file is below:

DEVICE=bond0
IPADDR=192.168.1.1
NETMASK=255.255.255.0
ONBOOT=yes
BOOTPROTO=none
USERCTL=no

After the channel bonding interface is created, the network interfaces to be bound together must be configured by adding the MASTER and SLAVE directives to their configuration files. The configuration files for each of the channel-bonded interfaces can be nearly identical.

For example, if two Ethernet interfaces are being channel bonded, both eth0 and eth1 may look like the following example:

DEVICE=ethN
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes
USERCTL=no

They key component in each Ethernet interface configuration is the MASTER directive. This indicates that ethN is a slave to bond0.

For a channel bonding interface to be valid, the kernel module must be loaded. To ensure that the module is loaded when the channel bonding interface is brought up, create a new file as root named bonding.conf in the /etc/modprobe.d/ directory. Note that you can name this file anything you like as long as it ends with a .conf extension. Insert the following line in this new file:

alias bondN bonding

Replace N with the interface number, such as 0. For each configured channel bonding interface, there must be a corresponding entry in your new /etc/modprobe.d/bonding.conf file.