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From: Renato Golin (rengolin_at_[hidden])
Date: 2006-09-07 05:46:25


On 9/7/06, Paul Fons <paul-fons_at_[hidden]> wrote:
> I would be happy if I could just solve this problem, but I do have
> another (more complicated) question. Soon I will have yet another
> remote machine (a new "woodcrest" quad core macintosh) to connect
> to. The two remote machines have two NICs. Routine communications
> are set within the OS to use en0 (ethernet 0). I would like openmpi
> to use en1 on the remote boxes and en0 on my main box (dual 3 GHz
> G5's) as I only have a single NIC on the main box.

Hi,

I'm not a MPI expert but I guess this is more of a OS problem than MPI
itself. You can force MPI to use one NIC instead of the other but that
wuold lead with route problem that the OS would not be able to solve
(at least not nicely).

On unix you can tell which NIC should be used to which network and you
could create two sub-networks, plug each one on each NIC, tell unix
(using 'route') which NIC is to which sub-net and hope things work by
themselves.

This should work on both cases.

> To put it in
> other words, how can I specify a preferred interface on each box
> (hopefully not all from the command line!).

man route

and why not from the command line ? ;)

cheers,
--renato