Simple step by step guide how to assign multiple ip addresses to single NIC in RHEL/CentOS/Oracle (5/6/7)-IP Aliasing

Simple step by step guide how to assign multiple ip addresses to single NIC in RHEL/CentOS/Oracle (5/6/7):IP Aliasing

In this article we learn how to assign multiple ip addresses to single NIC in the linux system. Assigning multiple ip addresses to single NIC is called IP Aliasing. It is very important when we talk about IP based hosing. In the IP based hosting the requirement is multiple ip address ,we can do it using IP Aliasing. This is very cost effective solution.

Assigning multiple Ip addresses to single NIC step by step guide

The interface configuration file located to “/etc/sysconfig/network-scripts”. In this file you can find the interface name like ifcfg-ethY .Here Y is the interface no.in my case I have one interface ifcfg-eth0 and going to assign multiple ip addresses on this interface.ifcfg-eth0 interface is already assign a ip address(192.168.137.3).now we create a sub interface under ifcfg-eth0 and assign the ip address(192.168.137.5).

To assign multiple ip addresses first we create sub interface to execute the below command.

#cd /etc/sysconfig/network-scripts

#cp ifcfg-eth0 ifcfgeth0:1

Now open the ifcfg-eth0:1 file and change the device name and ip address like this.

[root@localhost network-scripts]# cat ifcfg-eth0:1

DEVICE=eth0:1

HWADDR=08:00:27:B2:1C:2E

TYPE=Ethernet

UUID=7ad94a19-502b-4b87-8511-2293efc21cdb

ONBOOT=yes

IPADDR=192.168.137.5

PREFIX=24

GATEWAY=192.168.137.1

NM_CONTROLLED=yes

BOOTPROTO=static

After doing the above steps to take affect the changing we need to restart the network service to execute the below command

#systemctl restart network

We can verify the configuration is properly configured or not using the below command.

[root@localhost ~]# ifconfig

eth0 Link encap:Ethernet HWaddr 08:00:27:B2:1C:2E

inet addr:192.168.137.3 Bcast:192.168.137.255 Mask:255.255.255.0

inet6 addr: fe80::a00:27ff:feb2:1c2e/64 Scope:Link

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

RX packets:404 errors:0 dropped:0 overruns:0 frame:0

TX packets:221 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:1000

RX bytes:39650 (38.7 KiB) TX bytes:30867 (30.1 KiB)

eth0:1 Link encap:Ethernet HWaddr 08:00:27:B2:1C:2E

inet addr:192.168.137.5 Bcast:192.168.137.255 Mask:255.255.255.0

UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1