Can ssh service be accessed in private network?

My friend has a ssh server in a private network (ip address is 10.9.11.*), can this ssh server be accessed in public network? if it's possible, please tell me how to get it. thanks

Cosmore

Posted 2012-05-28T06:50:09.263

Reputation: 115

Answers

There's a few approaches i can think of to do it. In addition to Ignacio's solution of using nat, you could use reverse ssh tunneling - connecting out from your friend's server to your system, or a third one, or set up an ipv6 tunnel provider on the server as well as the client systems - i've done this with gogo6, and use the ipv6 address and tunnel for ipv6

Journeyman Geek

Posted 2012-05-28T06:50:09.263

Reputation: 119 122

The link you provided really helps, reverse ssh tunneling must follow 2 constraints: 1) source is public address, 2) source and destination both have ssh servers, right? Is it possible source is Windows with some kind of ssh server? – Cosmore – 2012-05-28T07:31:51.660

only the target would need it in a two system scenario, and the target and middle server in a 3 system scenario. It should work with windows and a ssh server - most windows ssh servers are simple openssh ports. – Journeyman Geek – 2012-05-28T07:39:39.027

Thanks, i think reverse ssh tunneling is the best solution in my scenario. – Cosmore – 2012-05-28T08:34:29.843

This has nothing to do with SSH. Private addresses such as 10/24 cannot be routed on the Internet, so some form of NAT must be used to make it available on a public address. Normally this is done with the "port forwarding" capabilities of a router or similar device.

Ignacio Vazquez-Abrams

Posted 2012-05-28T06:50:09.263

Reputation: 100 516

thanks Ignacio, i have little knowledge of NAT, is that means there must be a public host which can be accessed publicly to provide NAT function, so I can use the host address in the ssh client? – Cosmore – 2012-05-28T07:21:10.103

Not a public host, but a host with both public and private addresses, which can be used to forward the SSH connection to the final private address. – Ignacio Vazquez-Abrams – 2012-05-28T07:27:26.217

I got it, that's precisely what I want to say, thanks again, NAT means a second host is needed to build the connection. I use the forward host ip and port 10000 (for instance) in ssh client, the forward host maps port 10000 to the private destination A (with port B opened), is that right? – Cosmore – 2012-05-28T07:53:37.570

Sounds about right. – Ignacio Vazquez-Abrams – 2012-05-28T07:55:49.440