Additional ip address can be added to centos server.There are two ways we can add ip depending on whether network interface is controlled by network manager or not.Lets check if network manager is controlling the interface or not.Issue the following command to check the interface name.
ip addr show
Now issue the following command to check network manager is controlling the interface or not.
grep "NM_CONTROLLED" /etc/sysconfig/network-scripts/ifcfg-enp0s3
As you can see the output
which means network interface is controlled by network manager.Now follow the step to add the additional ip address.
Type following command
Select Edit a connection
then select Edit
Then click Add and add the desire ip address
As you can see in image we have added ip address 192.168.43.138
Now click OK and Quit
Now reboot your server check the new ip with following command
ip addr show
Above procedure is true if Network manager is controlling the interface.
But in case network interface is not controlled by network manager follow the below steps.
cp /etc/sysconfig/network-scripts/ifcfg-enp0s3 /etc/sysconfig/network-scripts/ifcfg-enp0s3:1
Edit the ifcfg-enp0s3:1 file
change the IPADDR field with desire ip
Save the file and reboot the system now you have successfully added the additional ip address.