Ssh – Create an SSH tunnel with authentication keys – Syntax

sshssh-keysssh-tunnel

I have to create an SSH tunnel to connect a deployment server to an VPN:

DeploymentServer --> Gateway --> PrivateServer

Each machine using a key, I tried the following command:

myMachine $ ssh -i GATEWAY_KEY.pem -N -L 1122:ubuntu@SERVER_PRIVATE_IP:22 ubuntu@GATEWAY_IP

And then this one in other terminal window:

myMachine $ ssh -i PRIVATE_SERVER_KEY.pem -p 1122 ubuntu@SERVER_PRIVATE_IP

But it doesn't work, I get a timeout error. My port 1122 is open and I can SSH it. I don't what I'm doing wrong, is my syntax correct?

It's my first tunnel so don't laugh at me!

EDIT 1

I added -v and fixed the second SSH call.

First call:
myMachine $ ssh -i GATEWAY_KEY.pem -N -L 1122:ubuntu@SERVER_PRIVATE_IP:22 ubuntu@GATEWAY_IP -v
Response: debug1: Authentication succeeded (publickey).

Second call:
myMachine $ ssh -i PRIVATE_SERVER_KEY.pem -p 1122 ubuntu@localhost -v

debug1: Reading configuration data /etc/ssh_config
debug1: /etc/ssh_config line 20: Applying options for *
debug1: Connecting to localhost [::1] port 1122.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file .ssh/wamapi_staging.pem type -1
debug1: identity file .ssh/wamapi_staging.pem-cert type -1
ssh_exchange_identification: Connection closed by remote host

And in the first tab again:

debug1: Connection to port 1122 forwarding to ubuntu@10.0.5.128 port 22 requested.
debug1: channel 2: new [direct-tcpip]
channel 2: open failed: administratively prohibited: open failed
debug1: channel 2: free: direct-tcpip: listening port 1122 for ubuntu@10.0.5.128 port             22, connect from ::1 port 60341, nchannels 3

Best Answer

I made it work using the .ssh/config file instead of trying to put all my parameters in my commands. Here is the results if someone needs it:

Host the-gateway
  Hostname GATEWAY_IP
  Port 22
  User ubuntu
  IdentityFile ~/.ssh/keys/GATEWAY_KEY.pem

Host the-tunnel
  Hostname localhost
  Port 1122
  User ubuntu
  IdentityFile ~/.ssh/keys/PRIVATE_SERVER_KEY.pem

And then the 2 commands:

ssh -N -L 1122:SERVER_PRIVATE_IP:22 the-gateway
ssh the-tunnel

Doing that way, SSH can use my pem keys.

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