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Subject: [OMPI users] which eth interface does mpi use by default when torque supplies it with a hostfile?
From: Rahul Nabar (rpnabar_at_[hidden])
Date: 2010-05-28 17:29:18

Each of our servers has twin eth cards: 1GigE and 10GigE. How does
openmpi decide which card to use while sending messages on? One of the
cards is on a 10.0. IP address subnet whereas the other cards are on a
192.168 adress subnet. Can I select one or the other by specifying the
--host option with the correct IP addresses?

How does it select the default though? Frequently I call mpirun from
within a PBS wrapper and then there is no explicit --host directive.
(I think PBS somehow communicates to mpirun what the assigned hostfile
is) In such a case though, which interface will mpirun use?