A friend and I were talking about creating a virtual network connection. In this case, we were thinking about defining two IPs on one physical Network Interface Card (NIC). I will use the FastEthernet interface, hme, as an example.
#vi /etc/hostname.hme0
esofthub
For the virtual
#vi /etc/hostname.hme0:1
esofthub-virt
To activate virtual connection without rebooting
#ifconfig hme0:1 plumb
#ifconfig hme0:1 inet 192.xxx.xx.xx netmask 255.255.255.0 broadcast 192.xxx.xx.xx
#ifconfig hme0:1 up
#ifconfig -a
Ensure that you populate the name service (files, nis, nis+, etc) with the virtual's IP address.