Installing a SSH server on Ubuntu

An ssh server allows you to remotely access your machine.
You'll have access to the remote console (equivalent to telnet, but secure) and the transfer of files (equivalent to ftp, but also security).

Installation

We can not be much easier: sudo aptitude install ssh

That's it!
You can now connect remotely in a secure way.

Use the login/password of users reported in Ubuntu.

Connection

You can use ssh command line: ssh mylogin@ipaddress

You can also access it from Windows:

with Putty for the command line: http://en.kioskea.net/telecharger/telecharger 918 putty
with WinSCP to transfer files: http://en.kioskea.net/telecharger/telecharger 3382 winscp

SSH through a proxy

First install the package connect-proxy:

sudo aptitude install connect-proxy

Edit /etc/ssh/ssh_config to enable SSH via proxy:

sudo echo 'ProxyCommand /usr/bin/connect-proxy -4 -S monproxy.domaine.com:port %h %p' >> /etc/ssh/ssh_config

Be sure to replace "proxy.domaine.com" and "port" with the name of your proxy and port number.
Tip

To run the ssh server on another port which the port 22 standard:

1. Open the configuration file: sudo gedit/etc/ssh/sshd_config
2. Locate the line Port 22 and replace by the value of your choice (eg port 741)
3. Restart the ssh server: sudo/etc/init.d/ssh restart

This little trick ensures that the server is identified by a scan of IP address ranges, and thus reduce some risks.