In today's digital landscape, ensuring network infrastructure is as reliable as possible is paramount. Redundant network configurations play a crucial role in ensuring service availability and minimizing downtime. In this article, we'll focus on creating a redundant network configuration on the CentOS 7 operating system using Bonding and VLAN (Virtual Local Area Network) technologies.

Fundamentals and Prerequisites

Before we begin, it's important to have a basic understanding of what Bonding and VLAN entail and how they can contribute to network redundancy.

• Bonding is a method of combining multiple network interfaces into one logical interface to increase throughput and/or provide connection redundancy.

• VLAN allows you to divide a single physical network interface into multiple virtual network segments, increasing security and enabling more efficient network management.

To implement this guide, you'll need:

1. CentOS 7 installed on a server with at least two physical network adapters.
2. Access to the server with superuser (root) privileges.

Installation and Configuration

Step 1: Installing Tools

First, you need to install the necessary tools. Open a terminal and enter the following command:

yum install -y teamd libteam

 

Step 2: Configuring Bonding

1. Create a new configuration file for the bond interface. Example for bond0:

   nano /etc/sysconfig/network-scripts/ifcfg-bond0
   ​

2. Insert the following configuration into this file, where em1 and em2 are the names of the physical network interfaces that will be part of the bond interface:

   DEVICE=bond0
   TYPE=Bond
   BONDING_MASTER=yes
   IPADDR=192.168.1.10
   NETMASK=255.255.255.0
   ONBOOT=yes
   BOOTPROTO=none
   BONDING_OPTS="mode=1 miimon=100"
   ​

3. Set up the physical network interfaces to be part of the bond interface:

   nano /etc/sysconfig/network-scripts/ifcfg-em1
   ​

Insert

TYPE=Ethernet
BOOTPROTO=none
ONBOOT=yes
MASTER=bond0
SLAVE=yes

Repeat for em2 and any other interfaces you wish to add.

Step 3: Configuring VLAN

1. Now, we'll create a VLAN interface on bond0. Example for VLAN ID 100:

   nano /etc/sysconfig/network-scripts/ifcfg-bond0.100
   ​

2. Insert the following configuration:

   DEVICE=bond0.100
   BOOTPROTO=none
   ONBOOT=yes
   IPADDR=192.168.100.10
   NETMASK=255.255.255.0
   VLAN=yes
   ​

Step 4: Activating the Configuration

After configuring bonding and VLAN, restart the network services:

systemctl restart network

Verification

To verify that bonding and VLAN are functioning as expected, use the following commands:

• Check the status of the bond interface: cat /proc/net/bonding/bond0
• Verify IP address configuration: ip addr show

You should see that your bond interface and VLAN segments are properly configured and active.

 

Creating a redundant network configuration using Bonding and VLAN on CentOS 7 can significantly improve the availability and reliability of your network infrastructure. This guide walked you through the basic steps necessary to set up these technologies. With this configuration, you can reduce the risk of service outages and increase the efficiency of your network management.