From Mexico.purplecow.org
This dumps config in a format similar to /etc/hostname.blah
ifconfig -a configinfo
$ ifconfig -a configinfo
lo0 inet plumb mtu 8232 index 1 addif 127.0.0.1 netmask 0xff000000 up
qfe1 inet plumb mtu 1500 index 6 addif 192.168.1.2 netmask 0xffffff00 broadcast 192.168.1.255 up