Our MAS was installed with two NICs, one internal and one external.  It's in the Server-Gateway config.  Teleworker works fine, but I'm now concerned with the security of the built in Linux firewall.  I see there are other options where you can put the MBG on a different server in the DMZ, which is way better in my opinion.
Are there firewall settings for the MAS?  I can't find anything.  I can ping my external IP, which I'd like to disable.  I can also access the 'My Unified Communications' portal from the Internet, which I don't want.  
-PM.