Comments on: Creating a Permanent SSH Tunnel Between Linux Servers

By: kat

kat — Thu, 21 Jan 2010 00:04:54 +0000

I’m still looking for help on related issue….This is scenario:

I’m on my laptop, I want to run GUI that is on serverB.
I do not have direct access to serverB. I do, however, have access to serverA and from there can get to Server B.

For comman line stuff…I use putty to get to ServerA, and ssh to ServerB. How do I set up tunnel to be able to use VNCclient on my laptop to run vncserver on ServerB.

I know how to create putty tunnel to serverA in order to run vncserver on serverA. But how to do it when I have to get to ServerB thru serverA.

Anyone?

By: John

John — Fri, 15 Jan 2010 20:39:58 +0000

I did some slight modification to the checking script, to get rid of the 2 port requirement, and to make it command line parameter driven.

#!/bin/bash

tunnel_entrance_port=$1
tunnel_end=$2
destination=$3
destination_port=$4

## use nc to connect to tunnel entrance port. If it returns non-zero, then create a new connection
nc -w1 localhost $tunnel_entrance_port
if [[ $? -ne 0 ]]; then
echo Creating new tunnel connection
/usr/bin/ssh -f -N -L $tunnel_entrance_port:$destination:$destination_port $tunnel_end
if [[ $? -eq 0 ]]; then
echo Tunnel to $destination through $tunnel_end created successfully
else
echo An error occurred creating a tunnel to $destination through $tunnel_end was $?
fi
fi

By: adhit

adhit — Thu, 06 Aug 2009 09:18:28 +0000

Heya,

Thanks for the information

It really works for me ..

By: PermaSSH

PermaSSH — Mon, 06 Jul 2009 11:09:55 +0000

Thanks for this workaround, but i think kNo has right with his comment or i´m not understand the use of local forwarding.

Another issue that´s confusing me is that u don´t use the -i option in your ssh-commands:
/usr/bin/ssh -p 19922 tunnel@localhost ls
AND
/usr/bin/ssh -f -N -L13306:hostb:3306 -L19922:hostb:22 tunnel@hostb
Shouldn´t it be for example: “/usr/bin/ssh -p 19922 – i /home/tunnel/.ssh/id_rsa tunnel@localhost ls” ???

By: kNo

kNo — Thu, 12 Mar 2009 12:03:08 +0000

Thanks for the code, but there is a mistake:
/usr/bin/ssh -f -N -L13306:hostb:3306 -L19922:hostb:22 tunnel@hostb
sould be
/usr/bin/ssh -f -N -L13306:hosta:3306 -L19922:hosta:22 tunnel@hostb
or /usr/bin/ssh -f -N -L13306:localhost:3306 -L19922:localhost:22 tunnel@hostb
or
/usr/bin/ssh -f -N -L13306:127.0.0.1:3306 -L19922:127.0.0.1:22 tunnel@hostb

Greets from spain

By: Matt

Matt — Wed, 11 Mar 2009 23:37:59 +0000

I run multiple ssh tunnels between our internal servers and cloud-based (e.g. EC2) servers and have found autossh to be the cat’s meow. Check it out http://www.harding.motd.ca/autossh/

By: Secure mysql replication between colos over an ssh tunnel :: Jaisen Mathai

Secure mysql replication between colos over an ssh tunnel :: Jaisen Mathai — Fri, 10 Oct 2008 22:07:28 +0000

[...] and tricks to creating a persistent ssh tunnel. I came across several methods but liked the one proposed by Brandon Checketts the best. You should, of course, create an unprivileged user (named tunnel perhaps) on both [...]

By: Anonymouse

Anonymouse — Wed, 20 Aug 2008 12:39:37 +0000

Thanks for this! I could have made this work, I’m sure, but it’s always nice to find the solution you’re looking for as the first result on Google.

By: Brandon

Brandon — Fri, 06 Jun 2008 21:47:26 +0000

FWIW, I had the network connection interrupted for a bit this morning, and the tunnel came back up perfectly once the network was back up. The MySQL replication going over it also worked flawlessly, re-establishing the connection and picking up where it left off.

I love it when things work like they should.