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I have three systems: my laptop, a login node, and a compute cluster.

The compute cluster does not have internet access. The login node does. If I run my simulation program on the login node, I can connect to its IP address (e.g. from my laptop on port 6789 to receive live simulation data.

What I want to do if forward all traffic from the compute cluster (e.g. internal IP of through, all on port 6789.

How can I do that?

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Just to be 100% clear - are you trying to connect to the compute cluster directly from your laptop, but through the login node? – growse Feb 28 '13 at 9:24
Yes. I'm sure there's got to be an easy way to do this... (I would ask the cluster administrator but it's 4:30 AM right now and I am trying to figure this out promptly). – Nick Feb 28 '13 at 9:26
So I'm assuming the login node has two NICs - one connected to the outside world, and the other connected to the cluster...? If so, I was originally thinking that you could just enable IP forwarding and (perhaps) NAT on the login node, but now I'm thinking that won't work unless the compute cluster treats the login node as it's primary gateway. – growse Feb 28 '13 at 9:28
Yes, I think it does have two NICs. – Nick Feb 28 '13 at 9:36

can you login via SSH to the Login node? If so, you can set up a route through the login node with: ssh -N -L user@loginhost. Then you can connect to localhost on port 40001 and you connect transparent to the cluster on port 6789. hope thats what you're looking for

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