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Subject: Re: [OMPI users] Cluster : received unexpected process identifier
From: Rohan Deshpande (rohand87_at_[hidden])
Date: 2012-04-05 03:58:44

I actually had too many Ethernet ports open.

When specify which Ethernet to use by btl_tcp_if_include the program works
like a charm :)

Thanks for inputs.


On Thu, Apr 5, 2012 at 8:11 AM, Jeffrey Squyres <jsquyres_at_[hidden]> wrote:

> On Apr 4, 2012, at 8:04 PM, Rohan Deshpande wrote:
> > Yes they are on same subnet. ips for example -,
> This is generally considered a bad idea, not just for MPI, but for Linux
> in general. Google around about this. One reason, for example, is that
> there is no way to guarantee which IP interface traffic will actually be
> sent out. For example, if you open a socket to a peer IP address (e.g.,
>, which IP address will be used to create that socket -- .1,
> .2, or .3? There's no way to know.
> (this is actually exactly the scenario that OMPI was complaining about; it
> got a socket from an unexpected IP address, and therefore got confused and
> basically said, "hey human, go figure this out")
> You need to put your IP interfaces on different IP subnets. E.g., have
> eth0 on 192.168.1.x/24, eth1 on 192.168.2.x/24, and eth2 on 192.168.3.x/24.
> It depends on how your networks are configured and what hardware you have
> -- you can implement this with switch-based VLANs (e.g., the ports that the
> 1.x wires go into are hard-wired to VLAN 10, the ports that the 2.x wires
> go into are hard-wired to VLAN 20, etc.), or using multiple switches (e.g.,
> each 1.x wire goes to switch A, each 2.x wire goes to switch B, etc.).
> Make sense?
> --
> Jeff Squyres
> jsquyres_at_[hidden]
> For corporate legal information go to:
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> users mailing list
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Best Regards,