Installed Version - XigmaNAS-x64-LiveCD-9.0.0.1.43.ISO

Secure Shell (SSH) is a network protocol that allows data to be exchanged using a secure channel between two networked devices.

There are multiple mechanisms for transferring files using the Secure Shell protocols.

• SSH File Transfer Protocol (SFTP), a secure alternative to FTP (not to be confused with FTP over SSH).
• Secure copy (SCP), which evolved from RCP protocol over SSH.

SSH is a protocol that can be used for many applications across many platforms including UNIX, Microsoft Windows, Apple Mac and Linux. Some of the applications below may require features that are only available or compatible with specific SSH clients or servers. For example, using the SSH protocol to implement a VPN is possible, but presently only with the OpenSSH server and client implementation.

• For login to a shell on a remote host (replacing Telnet and rlogin).

• For executing a single command on a remote host (replacing rsh).

• secure file transfer.

• In combination with rsync to backup, copy and mirror files efficiently and securely.

• For forwarding or tunneling a port (not to be confused with a VPN which routes packets between different networks or bridges two broadcast domains into one.).

• For using as a full-fledged encrypted VPN. Note that only OpenSSH server and client supports this feature.

• For forwarding X from a remote host (possible through multiple intermediate hosts).

• For browsing the web through an encrypted proxy connection with SSH clients that support the SOCKS protocol.

• For securely mounting a directory on a remote server as a filesystem on a local computer using SSHFS.

• For automated remote monitoring and management of servers through one or more of the mechanisms as discussed above.

• For secure collaboration of multiple SSH shell channel users where session transfer, swap, sharing, and recovery of disconnected sessions is possible.

Before deploying SSH you should be familiar with:

• Linux file and directory permissions.
• Mounting and detaching (unmounting) filesystems.
• Changing File Permissions and File Ownership.

Open a Terminal (Console, CLI) on your client PC and make sure you understand these commands:

• man mount
• man umount
• man chown
• man chmod
• man ssh

You can also look them up on FreeBSD.org's Man Pages.

See SUG Section 2.3-Installing XigmaNAS on disk.

Or you may run it from the CDROM as required for testing.

See SUG Section 2.2-Using XigmaNAS with the CDROM and a removable disk (LiveCD mode).

For details see SUG Section 6.4-Service SSH

1 - Enable SSH, then select the Options you will use.

2 - Configure the DSA Private Key if you wish to use key based authentication (not necessary if you will use keyboard interactive authentication). For details about configuring Key Authentication please read SUG Section 2.6.4-Password-less & Key Authentication.

3 - Click the “SAVE & RESTART” Button to write your changes to the NAS4Free configuration file. The SSH daemon should now be running.

Connect your Client to the Network, and use PING to verify that you can reach the Server's IP Address. You can also try to open the NAS4Free WebGUI, if you are successful then you have a working connection.

Most *nix distributions come with an SSH client already installed. Windows does not and you will have to find and install a command line SSH client to follow the steps below.

1. Determine the Server's IP Address. My NAS4Free IP Address is 192.168.1.250, the default.
2. Open a terminal session in *nix or a DOS prompt in Windows and enter the following:

   ssh -l //login-name// 192.168.1.250

You will then be prompted for your password unless you are using key authentication. If everything goes well you will now be connected to your NAS4Free server.

SSH uses the same commands as a *nix terminal or console. Below are some of the most common ones you might need.

• / - refers to the root directory on the server.

• ./ - refers to the current directory that you are in.

• ../ - referes to the parent directory of your current directory.

• pwd - shows what your current directory is - giving the full path.

• ls - lists all the files in your current directory.

• ls -al - lists filenames + information.

• ls -aR - lists filenames + information in all subdirectories.

• ls -aR | more - lists filenames + information in all subdirectories, pausing when the screen becomes full.

• ls -alR > result.txt - lists filenames + information and outputs the results to a file.

• ls *.html - lists all files ending with .html.

• ls -al/home/usr/sam/ - lists files + info for /home/usr/sam.

• cd - changes you to a new directory.

• cd / - changes you to the root directory.

• exit - exits ssh.

• mv [old name] [new name] - move/rename a file.

• cp [filename] [new filename] - copy a file.

• rm [filename] - delete a file.

• mkdir [directoryname] - creates a new directory.

• ls -d */ - lists all directories within current directory.

• cp -r [directoryname] [new directoryname] - copy a directory and all files/directories in it.

• rm -r [directoryname] - remove a directory. You will be prompted to answer “Yes” or “No” for whether you would like to delete each file in the directory.

• rm -rf [directoryname] - remove a directory and all files and folders in it (no prompting).

• find / -name [filename] - search the whole server for a file.

• find ./ -name [filename] - search for a file starting with the current directory.

• grep [text] [filename] - search for text within a file.

Example Session:

larry@larry-laptop:
$ ssh -l ldkraemer 192.168.1.250
ldkraemer@192.168.1.250's password:
Last login: Sat Jul 31 11:23:09 2010 from 192.168.1.200
Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994
The Regents of the University of California. All rights reserved.
 
Welcome to NAS4Free!
 
$ ls
CF_Data_Part2 mysata ramdisk1 ramdisk2
$ exit
Connection to 192.168.1.250 closed.
larry@larry-laptop:

References:

• Learn UNIX in 10 minutes. From freeenginner.org
• Common SSH Commands - Linux Shell Commands