This recipe shows you how to bind multiple IP addresses to a single Ethernet device. The ability to assign more than one address to the same device can be useful-the most obvious benefit is that you don't need to procure multiple Ethernet cards. The cost of hardware has dropped substantially, but IT budgets still run tight. Perhaps a less obvious benefit, but one more valuable, is the greater flexibility it gives when configuring network services. Different services, such as e-mail and websites, can run on the same system but be accessed using different addresses.
This recipe requires a CentOS system with a working network connection. It assumes that your primary Ethernet device is enp0s3 and is configured with a static IP address. You'll also need administrative privileges provided by logging in with the root account.