How to access services running locally on a remote server

The problem

Here is description of imaginary situation we want to solve.

• You have access via SSH to server server with hostname foobar-server.
• The foobar-server is running some service – HTTP Server, a database or something different. For instance, let’s pretend you are running Mongo database, but it doesn’t actually matter.
• Some firewall is set up around foobar-server, preventing you from accessing these services. Or maybe simply ports of these services are closed.
• You want to access this service from another machine – What can we do?

Create SSH Tunel

We can establish SSH tunel between our machine and foobar-server. Let’s get right on it, it’s just one command.

You might use this in following situation:

• your_user is username you use to access the foobar-server.
• foobar-server is hostname of the server running your service. Ofcrouse you can just as fine use directly its IP address.
• You want to access service running on port 27017 on the foobar-server. The way you could do that after running this command is by communication with 127.0.0.1:27077. Hence the structure of 27077:localhost:27017 represents local-port:target-host:target-port.

As a result, illusion that you are only accessing a service running locally on your machine. But what is actually really going is that

1. your data is encrypted,
2. sent through SSH Tunel to foobar-server,
3. foobar-server decrypts the data
4. foobar-server redirect decrypted data to target-host:target-port

And ofcourse, the same happens the other way around to deliver you the response from the service.