Create a virtual interface in Solaris

Virtual interfaces allow a single ethernet interface to listen on additional IP addresses.

Given an ethernet interface hme0 (use ifconfig -a to identify the names of your interfaces), you can create a subinterface called hme0:1 with the following command:

ifconfig hme0:1 plumb

You can set the IP address of the interface to 192.168.1.15 and turn on the interface with the following command:

ifconfig hme0:1 192.168.1.15 up

Unless you do some additional nonstandard things in your network, all of the subinterfaces on a physical interface need to be in the same subnet.

To make the virtual interface persist following a reboot, you can add the ip address or hostame from /etc/hosts in the file /etc/hostname.hme0:1

Source : http://www.tech-recipes.com/rx/35/create-a-virtual-interface-in-solaris/