Thanks to those who pointed out that I needed to use the "alias" parameter
to ifconfig to create virtual interfaces.  However, I still cannot make it
work.

The "alias" parameter is listed in the ifconfig man page, but seems to have
no effect when used.  Ifconfig did not return an error, but it appeared to
do nothing.  I expected to see a "new" interface show up in 'ifconfig -a'
output, and didn't see any.

Please sanity check me:
My stock qe0 interface is already, say, 192.168.1.x.  I tried to do
'ifconfig qe0 inet 192.168.1.y alias up' with no errors, but no success
either.

thanks,
Jonathan