Yes thats what I did before and found out this to be exact:
"sudo: ufw: command not found"


On Fri, Jun 28, 2013 at 11:50 AM, Pavan Balaji <balaji@mcs.anl.gov> wrote:

IIRC, Ubuntu has a firewall setup by default.  Try this:

% sudo ufw status

 -- Pavan


On 06/27/2013 09:48 PM, Syed. Jahanzeb Maqbool Hashmi wrote:

As I already read some discussion on the mpich thread and I came to know
these questions before:

  * *Can you ssh from "node01" to "node02"?*

    Yes I have passwordless ssh from each node to other (and vice versa)
  * *Make sure the firewalls are turned off on all machines.*

    I am using Ubuntu Linaro, 12.04, and I have no firewall installed on
    all the nodes.


Any other workaround :(

On Fri, Jun 28, 2013 at 11:43 AM, Pavan Balaji <balaji@mcs.anl.gov
<mailto:balaji@mcs.anl.gov>> wrote:


    On 06/27/2013 09:41 PM, Syed. Jahanzeb Maqbool Hashmi wrote:

        MPID_nem_tcp_connpoll(1826): Communication error with rank 0:
        Connection
        refused


    Sounds like a firewall problem.

    http://wiki.mpich.org/mpich/__index.php/Frequently_Asked___Questions#Q:_My_MPI_program___aborts_with_an_error_saying___it_cannot_communicate_with___other_processes