General Questions

Is m0n0wall compatible with B2MM? I get the message.

back to My Mac isn't working properly because it requires a router that supports Port Mapping Protocol (NAT-PMP) or Universal Plug and Play (UPnP).

Thanks,
-marc

Looking at the pages for B2MM I would say no.  Monowall doesn't support UPnP or NAT-PMP Unfortunately there does not appear to be a way of manually configuring the router to work with B2MM without these features.