Place to share anything

The traditional Unix application used to establish a terminal connection to a remote machine over the network is known as telnet. The telnet application connects to a telnet daemon running on a remote system and creates a login session once the proper authentication credentials have been exchanged.

Unfortunately, authentication information and all other data exchanged between a telnet client and server is exchanged in the clear, meaning that it is readily visible to anyone with access to your network, a packet sniffer, and sufficient curiosity or other motivation. There are ways around this, of course: You can use telnet through an encrypted virtual private network (VPN) or tunnel, or install a version of telnet that uses Kerberos authentication, but why cling to an old application and protocol when there are newer, more secure alternatives available?

The newer, more modern, and secure replacement for telnet is ssh, the secure shell application, which uses SSH, the Secure Shell protocol. The ssh application is installed as part of a default Ubuntu Linux installation, along with other applications that use the same protocol and authentication information, and which shares much of the same command-line syntax, such as sftp (secure FTP) and scp (secure copy).

Using ssh, you can establish a remote login session on any machine that is running an ssh daemon. An ssh daemon must be running on the remote system. If you try to connect to the remote system and see a message like the following, the ssh daemon is either not running on that system or it is running on some port other than the default port 22:

$ ssh ulaptop
ssh: connect to host ulaptop port 22: Connection refused

The remainder of this section discusses how to use ssh to connect to remote systems that are actually running the daemon. Using ssh to connect to a remote system as the current user is as simple as typing the ssh hostname command, where hostname is the name or IP address of the host that you want to connect to. The first time that you attempt to connect to a remote system that you have never connected to before, you will see
a message like the following:

$ ssh myserver
The authenticity of host ‘myserver (192.168.6.90)’ can’t be established.
RSA key fingerprint is 07:e6:3a:50:4b:6d:e6:d8:f1:80:c6:b2:da:02:a3:da.
Are you sure you want to continue connecting (yes/no)?

To continue connecting to this system, type yes and press return. The ssh utility adds the RSA key for then remote system to its list of known hosts (to prevent some other machine from impersonating the remote machine in the future), and prompts you for your password, as in the following example:
Warning: Permanently added ‘myserver’ (RSA) to the list of known hosts.

test@myserver’s password

Now you are logged in to your remote computer from your Ubuntu desktop.

Related posts:

1. SoftPerfect Network Scanner 4.4.1 – Free Network Monitoring Tool For you who keep monitoring the home network or working...
2. How to configure the network connection on Mandriva 2010 After made a fresh Mandriva 2010  installation on my desktop...
3. How to enable Access to Virtual Windows 7 from Local Network Last time I was installed a virtual Windows 7 inside...
4. How To configure DHCP server on Ubuntu system This tutorial will show you how to configure the...
5. Ubuntu versus Mint – a Direct Comparison Review Just for your information, Linux Mint was built based...

Related posts brought to you by Yet Another Related Posts Plugin.