Where to start learning ssh?

Question

SSH

I want to deal with ssh, in theory everything is more or less clear. But how can I practically try to connect using ssh if I don’t have a server, but only a PC. Do not offer remote hosting, perhaps there are test servers, especially for such tasks that are open to everyone? ubuntu system 14.04

Answer 1

[email protected]: #> sudo apt-get install ssh tmux
[email protected]: #> ssh [email protected]
Login: user
Password: (blind typing, don't assume " nothing is being typed")
Welcome to Linux at localhostname
blablabla
that's all. Learn more about standard Linux commands.

Answer 2

What's wrong with localhost (it's your own system!)?
ssh [email protected]
You can even get a dozen different users on it and walk on them.
Well, radically - put yourself a virtual machine with any Linux.

Answer 3

you can still lift the container), fall into the rabbit hole. Enter the container, connect via ssh to another user in the system, from there connect via ssh to the first user, then log in from under the root to other users, etc.
but in principle man ssh and I would also suggest trying to automatically connect ssh without entering a password ( www.linuxproblem.org/art_9.html). After seeing what autossh is, why and how it is configured, it works.

Answer 4

What exactly do you mean by "learning ssh"?
If I understand you correctly, then for example you can try to play with the capabilities of ssh.
1. Still, put virtualbox, and ubuntu is tighter in it, only server, without gui. If you have an Internet connection through a router, then in the virtual machine in the network settings, set the connection type to "network bridge", so you will ensure that your virtual machine will be exactly the same computer on the network as your physical machine. If the connection is direct, without a router, then select the NAT connection type. There, already see what address virtualbox will give to the machine. (It seems that the guest machine from the host should be available).
/further in the explanations, we will assume that you are connecting through a router that gives addresses from the network 192.168.0.0/
2.ssh [email protected](Let's say your virtual machine received such an address). Here you are connected!
3. Try to install remotely, for example htop. Run htop, see what is running on your remote machine.
4. Read on Habré, for example, how to organize a connection not by password, but by keys.
5. Try to implement a keyed connection.
6. Try installing a web server from the repositories, such as apache. It will give you the simplest web server with default settings, you will type the address of your virtual machine in the browser and the web server will give you an example page. Here, you have already installed a web server using ssh :-)
7. Read this article, for example https://m.habrahabr.ru/post/122445/ Try to implement dynamic port forwarding (described in the article). Now you have learned how to organize a simple socks-proxy using ssh :-)
PS: learn from examples. Everything I've written is just off the top of my head. Good luck!