On Fri, Nov 6, 2009 at 2:39 AM, Jeff Squyres <jsquy...@cisco.com> wrote: > On Nov 5, 2009, at 11:28 AM, Lee Amy wrote: > >> I remembered MPI does not count on TCP/IP but why default iptables >> will prevent the MPI programs from running? After I stop iptables then >> programs run well. I use Ethernet as connection. >> > > > Note that Open MPI *can* use TCP as an interface for MPI messaging. It > definitely uses TCP for administrative control of MPI jobs, even if TCP is > not used for MPI messaging. Open MPI therefore basically requires the > ability to open sockets between all nodes in the job on random TCP ports. > > Your could probably configure iptables to "trust" all the machines in your > cluster (i.e., allow TCP sockets to/from random ports) but disallow most > (all?) TCP connections from outside your cluster, if you wanted to...? > > -- > Jeff Squyres > jsquy...@cisco.com > > _______________________________________________ > users mailing list > us...@open-mpi.org > http://www.open-mpi.org/mailman/listinfo.cgi/users >
Thanks. And actually I don't know if I need to disable iptables to run MPI programs properly. Obviously from your words Open MPI will use random ports so how do I set up in iptables then let trusted machines open their random ports? Regards, Amy
