On Sat, 24 Jul 2010 16:31:12 -0700, Ralph Castain <r...@open-mpi.org> wrote:
On Jul 24, 2010, at 4:40 PM, James wrote:
OK, that's the problem. I turned the firewall off on both machines, and
it works.
Now the question: how do I fix it? I searched through the archives, and
found that it seems to be a pretty common problem. Unfortunately, I
didn't
see a solution that I could understand. (I'm not a sysadmin, just a
person
trying to do some programming.)
I have a couple of machines on a local net, with IP addresses in the
192.168.10.1xx range. There's a router at 192.168.10.1, which is
connected
to the internet via a cable mode. So how do I set up my system so my
local machines can do whatever talking between themselves that's needed
by
OpenMPI, while still having a firewall between my system and the outside
world?
Here's what seems to be a solution that works for SuSE. May be something
similar for other systems:
1) Edit the file /etc/sysconfig/SuseFirewall2
2) Look for the keyword FW_TRUSTED_NETS
3) Add the IP addresses of your internal machines there. The format
for multiple machines is wierd: "192.168.10.0/8" means all machines
in 192.168.10.x. There doesn't seem to be any way to specify a
numeric
range, like .100 to .110.
4) Add the lines FW_SERVICES_TRUSTED_TCP="1:65535" and
FW_SERVICES_TRUSTED_UDP="1:65535"
5) Save the file. Bring up Yast2, and use it to stop and restart the
firewall.
Hope this is useful, as it took about 10-15 hours of my time, spread over a
week or so, to figure it out.
Most routers provide their own internal-to-external firewall - you might
check its setup and see. If it does, then you don't need to also have
one on your individual machines.
Seems to be the same problem as with the firewalls on the machines. That
is, there appears to be a firewall, but the little information in the
manual or online help assumes that you already have an expert sysadmin
level of knowledge.
James
