Best practices using ssh


SSH is a suite of network connectivity tools. Many users of telnet, rlogin, ftp, rcmd, rcp, and other such programs might not realize that their password is transmitted across the Internet unencrypted, but it is.  

It is trivial to eavesdrop on data as it passes through a network, this is known as "sniffing."  Packet sniffers decode most protocols on the internet. The "Ethereal" packet sniffer decodes over 500 protocols.

SSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other network-level attacks.  SSH consists of a number of programs:
sshd - Server program run on the server machine. 
ssh - This is the client program used to log into another machine or to execute commands on the other machine. 
scp - Securely copies files from one machine to another.
sftp - Secure file transfer program.