Are you asking about configuring a secondary IP address on the
same physical network card?
That would be configuring for virtual networks.
Example would be to have two IP addresses on say the same
Ethernet interface, like 18.104.22.168 and 22.214.171.124,
you would do the following as described from man pages:
ifconfig le1 plumb
Once a physical interface has been "plumbed", additional
local interfaces can be configured by simply naming them in
subsequent ifconfig commands. Logical interfaces do not
need to be "plumbed". Simply mentioning their name in an
ifconfig command is sufficient. For example, the command:
ifconfig le1 126.96.36.199
ifconfig le1:1 188.8.131.52
will allocate a logical interface associated with the physi-
cal interface le0. A logical interface can be configured
with parameters (address, netmask, etc.) different from the
physical interface that it is associated with. And logical
interfaces that are associated with the same physical inter-
face can be given different parameters as well. Each logi-
cal interface must be associated with a physical interface.
So, for example, the logical interface le0:1 can only be
configured after the physical interface le0 has been
Hope this helps,
" Been there, Done it, got a T-shirt "
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