The following config will help you to configure a virtual network interface to allow you to have multiple additional network IP address on a single hardware network interface. For example our RHEL server has currently a single hardware network interface called eth0
. This interface is used as a master network interface with an IP address of 10.1.1.110. To this network interface we will attach two additional virtual network interfaces eth0:0 - 10.1.1.111
and eth0:1 - 10.1.1.112
. Let’s get started by showing a current network configuration:
[root@rhel7 ~]# ip addr show

From the above output we can see that currently we have configured eth0 network interface only. Next, we are going to locate a corresponding network interface configuration file for eth0:
# grep -l DEVICE.*eth0 /etc/sysconfig/network-scripts/*

The configuration file responsible for the
eth0
network interface is /etc/sysconfig/network-scripts/ifcfg-eth0
[root@rhel7 ~]# cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE="eth0" NETBOOT="yes" HWADDR="08:00:27:15:38:B7" TYPE="Ethernet" BOOTPROTO="none" NAME="eth0" UUID="462f4834-4fe7-43a7-84e7-83b2722e94c1" ONBOOT="yes" IPADDR="10.1.1.110" NETMASK="255.0.0.0" GATEWAY="10.1.1.1"
In order to create a virtual network interface we can first copy a master configuration file /etc/sysconfig/network-scripts/ifcfg-eth0
and then edit its content to set an appropriate network interface name and IP address:
[root@rhel7 ~]# cd /etc/sysconfig/network-scripts/ [root@rhel7 ~]# cp ifcfg-eth0 ifcfg-eth0:0 [root@rhel7 ~]# cp ifcfg-eth0 ifcfg-eth0:1
Next, we need to edit DEVICE, NAME, IPADDR
in both virtual network configuration files. Below you can see both edited configuration files:
# cat /etc/sysconfig/network-scripts/ifcfg-eth0:0 DEVICE="eth0:0" NETBOOT="yes" HWADDR="08:00:27:15:38:B7" TYPE="Ethernet" BOOTPROTO="none" NAME="eth0:0" UUID="462f4834-4fe7-43a7-84e7-83b2722e94c1" ONBOOT="yes" IPADDR="10.1.1.111" NETMASK="255.0.0.0" GATEWAY="10.1.1.1"
and
# cat /etc/sysconfig/network-scripts/ifcfg-eth0:1 DEVICE="eth0:1" NETBOOT="yes" HWADDR="08:00:27:15:38:B7" TYPE="Ethernet" BOOTPROTO="none" NAME="eth0:1" UUID="462f4834-4fe7-43a7-84e7-83b2722e94c1" ONBOOT="yes" IPADDR="10.1.1.112" NETMASK="255.0.0.0" GATEWAY="10.1.1.1"
Once you have edited the additional virtual network interface files, all needs to be done is to restart your network. On RHEL7 linux server this can be achieved by:
[root@rhel7 ~]# systemctl restart network
Next, check your network settings again and look for two additional virtual network interfaces:
[root@rhel7 ~]# ip addr show

As a last and optional step you can test your newly configured virtual network interface with a
ping
command from some other host on your network: