IP aliasing is a concept where multiple IP addresses are assigned to the same physical network interface. IP aliasing is useful in several scenarios. When multiple small applications running on different servers need to be consolidated into a single large server, the individual IP address for each application needs to be mapped to the same physical interface. As the physical servers get virtualized, there is a need to support IP aliasing for the virtual machine instances also. In Linux, IP aliasing is accomplished by creating subinterfaces on a real interface.

In this recipe, we will see how multiple IP addresses can be allotted to a single virtual interface.