>>> > One idea comes to mind is whether the two nodes are on the same
>>> > subnet? If they are not on the same subnet I think there is a bug in
>>> > which the TCP BTL will recuse itself from communications between the
>>> > two nodes.
>> you are right - subnets are different, but routes set up correctly and
>> everything like ping, ssh etc. are working OK between them
> But it isn't a routing problem but how the tcp btl in Open MPI decides
> which interface the nodes can communicate with (completely out of the
> hands of the TCP stack and lower).
Do you know when it can be fixed in official OpenMPI?
Is patch available or something?