The practice of configuring multiple IP addresses on a particular network interface is called IP aliasing. IP aliasing is useful when you set up multiple sites on virtual web hosting on a single interface, or maintain multiple connections to a network each of which serves a different purpose. You can assign multiple IP addresses to one network interface from a single subnet or completely different ones.
All existing Linux distributions including CentOS supports IP aliasing. Here is how to bind multiple IP addresses to a single network interface on CentOS.
If you would like to set up IP aliasing on the fly, there are two ways to do it. One way is to use ifconfig, and the other method is to use ip command. Using these two methods, let me show you how to add two extra IP addresses to eth0. 继续阅读