Question about 'iwconfig wlanX ap' command

[Jerry]

Hello!

I have a "feed" link that is a client to an access point.  Its a 12 mile
link that isnt really "strong" but i get good throughput, so i presume that
there isnt packet loss.  Problem was, even though i would set the essid on
the client, it would sometimes roam to another AP (but still show the
correct essid).  It wasnt too secure anyway, so my solution was this:

on the AP I use:   iwpriv wlan0 maccmd 1   <- turns on mac filter
                           iwpriv wlan0 addmac 11:22:33:44:55:66  (where mac
is zcomax clone in client below.)

on the client i use: iwpriv wlan0 host_roaming 2   <- turns OFF roaming
                            iwconfig wlan0 ap 00:02:6f:aa:bb:cc  (where mac
is AP above)

The idea is to make these units a point to point link (my luck with Ad-Hoc
has been less than stellar), nothing else can associate to the AP, and the
client should ONLY associate to this particular AP.  And this works like it
should. but if the AP is rebooted, or gone for whatever reason for a short
period of time, the client will not re-associate. I have to log into the
client and : "iwconfig wlan0 ap 00:02:6f:aa:bb:cc" again for it to
reassociate.   Is this the fault of the host_roaming command?

To be honest I havent tried it without the host_roaming command (just the
iwconfig wlan0 ap command alone) to see if the iwconfig ap command was
enough.  My solution was to cron the iwconfig wlan0 ap command every 5
minutes, which is probably using a sledgehammer on a finishing nail.

suggestions, clarifications?

Thanks!
Jerryf