Managed Mode -- Use of wifi0 and wlan0 devices?

[Tony Espy]

I'm using HostAP in managed mode, in conjunction with an older DHCP 
client ( pump ).  I'm considering moving to ISC's dhclient, but for now 
I'm stuck with pump ( 0.8.21 ).

One of the first things I ran into was that when killed, pump marked the 
interface as DOWN.  Since HostAP requires one or more of it's device(s) 
to be UP in order function, I had to run some extra code to make sure 
"wlan0" was marked UP before associating with a new AP.

It also seems to me that the right way to handle changing IP addresses, 
is to mark the interface DOWN, muck with the IP parameters, then mark 
the interface UP.

So, I came up with the idea of using both HostAP devices; "wifi0" for 
association, and "wlan0" as my actual IP interface.  This allows 
toggling of "wlan0"'s UP/DOWN flag ( by pump, or other code ) without 
disabling the HostAP driver as "wifi0" remains UP and thus 
wpa_supplicant is free to do it's thing.

This seems to work great, although I wasn't able to find any 
documentation, nor threads on the mailing list re: running in such a 
configuration.

Am I correct to be using both HostAP devices in such a manner while in 
managed (STA) mode?

ciao,
Tony Espy,
Pepper Computer