Holger Bauer wrote:

>>
>>What do you have under:
>>Interfaces -> WAN -> Block Private Networks?
>>
> 
> No, block private networks is disabled. This even shouldn't matter for attemot 2 where LAN and OPT
is bridged.
> 

I made an installation with this same setup and had the same problem
today. Within the lan there's a router connecting a remote location
(obviously static routes on the monowall box are defined for it).

I found the filtering bridge working perfectly for connections coming
from the LAN itself, but the remote location is not able to reach the
machine in DMZ/OPT1, while it was able to correctly reach the monowall box.

Disabling the filtering bridge everything started to work.

Nothing appears in monowall logs (even enabling per-client rules
explicitly), so it seems not to be a filters-related issue.