TCP port forwarding using SSH

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December 4th, 2012, 10:59 PM

fuzzybunny

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TCP port forwarding using SSH

I did a quick forum search but couldn't find an answer to this one

How do I enable port forwarding using SSH?

I have three devices

1- Desktop Computer
2- Server B (named bems)
3- Router C

I want to be able to ssh from computer to Router C , through Server B; hence I need to set up port forwarding on Server B

(see attached image file)

I have tried this but this does not work:

unix Code:

Original - unix Code
server-b# ssh -L 2221:203.44.175.197:22 localhost

server-b# ssh -L 2221:203.44.175.197:22 localhost

... I keep getting "Fatal error, connection refused"

Aside - Socat

I have socat partially working and ssh is forwarded,

but each time I run my script that automates SSH, it crashes...

unix Code:

Original - unix Code
server-b# /opt/csw/bin/socat -ddd -v -ls -s -4 tcp-listen:2221 tcp-connect:203.44.175.197:22

server-b# /opt/csw/bin/socat -ddd -v -ls -s -4 tcp-listen:2221 tcp-connect:203.44.175.197:22

Attached Images

Drawing1.jpg (34.8 KB, 41 views)

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December 4th, 2012, 11:53 PM

E-Oreo

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From desktop computer you would run this in one terminal:

Code:

desktop$ ssh -L 2221:routerc:22 serverb

Then in a second terminal on desktop computer you would run this:

Code:

desktop$ ssh -p 2221 localhost

Leave the first terminal open to maintain the tunnel. The second terminal will be connected to routerc through serverb.

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