How to secure a wireless bridge?

[Scott Augustus <scott_(_at_)_visgen_(_dot_)_com>]

Greetings all,

I'm having some conceptual trouble determining how I can use IPsec to 
secure a wireless bridge setup I have.  This whole situation is plagued 
with pain for me as I determined that my current (somewhat antique) 
wireless bridge equipment, Aironet BRE500's, are ***not*** capable of 
doing WEP at 11Mbps.  This apparently has to do with the crummy radio 
card it uses.  Ugh!

Anyhow, I desperately need to secure these units.  Right now they are 
running entirely in bridge only mode creating a bridge between two 
facilities using the same subnet.  I got really excited by the IPsec 
bridge capabilities outlined in the man page for brconfig but am now 
conceptually stumped as to how I might implement this as the units are 
merely bridging the subnet together and work regardless of IP's at the 
moment... meaning, the wireless units are not acting as routers where 
traffic hits them at a certain IP and is forwarded on to the other, 
they're just bridged.

TIA,

~S~