Hi,
Consider another setup where the path A - B - C _ D - E is just one of many possible paths between A and E. Now the link C _ D is such a "hidden link" and nodes C and D are NATting all packets traveling along. Then, when E receives a packet from A which has passed along ABCDE the source address of that packet indicates that it came from B and not from A. The batmand on E might have choosen a totally different route back from E to A (e.g. E-J-B-A) but because the source address of the packet shows Cs IP it must be routed back along C.
Only packages for the bbs/bbc interface and 172er ips are considered. This is the same as you have already mentioned. If I SNAT also the OGMs (4305) routing is completely dead.
by the way. Since batmand-exp rv 730 the parametrization of --bmx-defaults is now enabled by default (it detects much better routes). This parametrization automatically hides all non-primary interfaces and announces them as HNA. You can revert the HNA announcements for a interface with the interface specific /A switch (since revision 747).
To be sure, if I add /A behind bbs then no HNA is created for this interface ip?
Bye Stephan