For OpenMPI users struggling with cluster/grid setups in combination
with particular networks to use or avoid, it may be useful to know
that the documentation on http://www.open-mpi.org/faq/?category=tcp
regarding the oob module is currently misleading. The options that
actually implement this functionality are "oob_tcp_include" and
"oob_tcp_exclude" (not oob_tcp_if_include and oob_tcp_if_exclude).
The confusion probably arises from the fact that for the btl
layer the "_if" does need to be included.