3 Added requested diagram, fixed port error
source | link

Then I would simply point Firefox to localhost:4003 and that would be my working proxy to access the website. However, because of the weird setup between System Bravo and System Charlie this will not work. ***It was pointed out to me a diagram displaying communications would make this easier. So here it is:

A full list of possible connections:
     ----->      --X-->       ----->
Alpha       Bravo      Charlie      Delta
     <--X--      <-----       <--X--

The connection between Alpha and Bravo and Charlie as it is currently 
configured:

     ProxyCommand ssh -q system.bravo nc localhost 1081
     -------------------------------------------------->      
Alpha    Bravo <---------------------------------------- Charlie
                      AUTOSSH -R 1081:localhost:22 

-----> = An allowed connection via SSH
--X--> = A blocked connection, only reverse SSH possible

Does anyone have a solution on how I can accomplish this keeping in mind the required proxy command and reverse SSH tunnel between System Bravo and System Charlie?

Thanks so much

PS: I hope my diagram helps, sorry that it is not a real image

Then I would simply point Firefox to localhost:4003 and that would be my working proxy to access the website. However, because of the weird setup between System Bravo and System Charlie this will not work. Does anyone have a solution on how I can accomplish this keeping in mind the required proxy command and reverse SSH tunnel between System Bravo and System Charlie?

Thanks so much

Then I would simply point Firefox to localhost:4003 and that would be my working proxy to access the website. However, because of the weird setup between System Bravo and System Charlie this will not work. ***It was pointed out to me a diagram displaying communications would make this easier. So here it is:

A full list of possible connections:
     ----->      --X-->       ----->
Alpha       Bravo      Charlie      Delta
     <--X--      <-----       <--X--

The connection between Alpha and Bravo and Charlie as it is currently 
configured:

     ProxyCommand ssh -q system.bravo nc localhost 1081
     -------------------------------------------------->      
Alpha    Bravo <---------------------------------------- Charlie
                      AUTOSSH -R 1081:localhost:22 

-----> = An allowed connection via SSH
--X--> = A blocked connection, only reverse SSH possible

Does anyone have a solution on how I can accomplish this keeping in mind the required proxy command and reverse SSH tunnel between System Bravo and System Charlie?

Thanks so much

PS: I hope my diagram helps, sorry that it is not a real image

2 Meaningful title
| link

SSH Tunnel MadnessBetween Multiple Hosts

1
source | link

SSH Tunnel Madness

This is slightly different than the other SSH questions I have seen on here so here it goes. I have a complex setup for accessing a web application and unfortunately there is no way around it. Here is the scenario and systems involved (IP addresses anonymized for obvious reasons):

System Alpha
System Bravo
System Charlie
System Delta

I need to communicate to a website available to System Delta from System Alpha. The problem is, I cannot talk to System Delta directly. Currently, I can SSH in to System Bravo, and I can SSH into System Charlie utilizing a proxy command which utilizes System Bravo as the proxy. To illustrate this, here is my SSH Config:

Host system.bravo
  User bob
  Hostname 1.1.1.1
  ForwardAgent yes

Host system.charlie
  User bob
  ForwardAgent yes
  ProxyCommand ssh -q system.bravo nc localhost 1081

System Charlie is accessible to System Alpha in this way because it has created a reverse SSH tunnel to System Bravo on port 1081. This is done because the firewall sitting between System Bravo and System Charlie ONLY allows SSH outbound to System Bravo. I know this is annoying, but it is a client requirement.

System Charlie can SSH into System Delta without issue. My problem is, how do I go about setting up a usable SOCKS proxy with SSH so that System Alpha can access a website only accessible from System Delta. Normally I would do it like this:

ssh -2 -C -D 4001 -L 4002:localhost:4002 -L 4003:localhost:4003 bob@system.bravo
ssh -2 -C -D 4002 -L 4003:localhost:4003 bob@system.charlie
ssh -2 -C -D 4003 bob@system.delta

Then I would simply point Firefox to localhost:4003 and that would be my working proxy to access the website. However, because of the weird setup between System Bravo and System Charlie this will not work. Does anyone have a solution on how I can accomplish this keeping in mind the required proxy command and reverse SSH tunnel between System Bravo and System Charlie?

Thanks so much