I have wired and wireless connections possible on a laptop.
What I would like to happen is it uses the full-duplex switched 100Mbit wired
link when it is plugged in, but fall back to 11Mbit wireless if I unplug it.

I can make this work manually by
su
ifdown eth0
unplug cable, plug in WiFi Cardbus
...
eject Cardbus, plug in cable

but that results in network connection being lost and applications failing.
DHCP and routing is "fun" as well, and I get two IP addresses from DHCP
(one for each MAC address) which confuses peer machines.

So can I set up a "bond0" device and add eth0 and wlan0 to it as slaves?
Then have DHCP and default route be via bond0 ?
How do I force bonding device switch back to faster wired link when it
becomes available again?

Seems bonding device isn't what I am looking for.
- It is an IP layer thing so you can't DHCP over it, and you can't add slaves till it has an IP.

Also while bond0 happily makes wlan0 the active device packets don't get though
my access point / switch