ssh port forward over three server

UNIX for Advanced & Expert Users
1

Hello there,

I have a big problem, and I hope somebody can help me. I try to realize a port forward over three server. Here is a picture...

Client Server1 | Server2
------- ------- | -------
|...... | |...... | | |...... |
|...... | |...... | | |...... |
|...... | |...... | | |...... |
|...... | |...... | | |...... |
------- ------- | -------

Server2 is behind a firewall. Server1 is able to connect via ssh to server2.
The Client is able to connect via ssh to Server1.

From Server1 I can make a port forward like this.

Server1> ssh -L 1111:server2:2222 server2

This works fine.
But I want to connect the Port 1111 from the Client.

Client> ssh -L 1111:server1:1111 server1
This did not help.
What is wrong?
All the servers are UNIX servers.

Many thanks for your help!

2

My guess it you can only ssh to server2 fron server1 due to a rule in the firewall.
You might want to try the forward from server1 to server2 and connecting with tour client to the (forwarded) port on server1.
(the forwarded port on the server may be bound to localhost, there might be an option to avoid this)

If you really can't access the port on server1 fron client, you can use two seperate ssh tunnels:
server1> ssh -L 2222:server2:1111
# Leave this one open
client> ssh -L 1111:server1:2222

This will forward port 1111 on client to port 2222 on server1, which is forwarded to port 1111 on server2.
(different port servers only as illustration)

3

I already tried that. It does not function. Somebody another idea?