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? -- Rahul
