wiki

Use the ifconfig command to create an IP alias. To have the alias created when the system starts, add the ifconfig command to the /etc/rc.net script.

The following example creates an alias on the en1 network interface. The alias must be defined on the same subnet as the network interface.

  # ifconfig en1 alias 9.37.207.29 netmask 255.255.255.0 up 

The following example deletes the alias:

  # ifconfig en1 delete 9.37.207.29 

For a persistent alias use better chdev command

  # chdev -l enX -a alias4=9.37.207.29,255.255.255.0

To delete a persistent alias:

  # chdev -l enX -a delalias4=9.37.207.29