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-====== Accessing computing resources remotely ======
-[ __[[vlsi:home|VLSI Home]]__ ]
-[ __[[vlsi:workbook|VLSI Design WorkBook]]__ ]
-[ __[[vlsi:computing_main#contents|Back to index]]__ ]
-== Contents ==
-   * [[vlsi:computing_remote#introduction|Introduction]]
-   * [[vlsi:computing_remote#connecting_to_a_vlsi_machine|Connecting to a VLSI machine]]
-   * [[vlsi:computing_remote#remote_connections_from_windows|Remote connections from Windows]]
-   * [[vlsi:computing_remote#remote_desktop_access_with_nx_client|Remote desktop access with NX Client]]
-   * [[vlsi:computing_remote#accessing_vlsi_machines_from_outside_the_infn_domain|Accessing VLSI machines from outside the INFN domain]]
-   * [[vlsi:computing_remote#remote_file_transfers|Remote file transfers]]
-   * [[vlsi:computing_remote#web_browsing_through_ssh|Web browsing through SSH]]
-   * [[vlsi:computing_remote#tips_and_tricks|Tips and tricks]]
-**Keywords:** ssh, X-server, scp, sftp, tunnelling
-===== Introduction =====
-Once you have obtained a VLSI computing account, you are not required to physically
-work in front of a VLSI machine. As a matter of fact, you can always access your VLSI
-machine remotely using the **[[http://en.wikipedia.org/wiki/Secure_Shell|Secure Shell (SSH)]]**
-connection protocol and just work as you would be in front of it. For security issues,
-VLSI and INFN machines allow remote access only through <nowiki>SSH</nowiki>. Connections
-using unsecured protocols such as <nowiki>FTP</nowiki> and Telnet are refused.
-This chapter describes how you can access the VLSI computing resources remotely (both from
-Linux/Mac or Windows machines) and gives further information about some common tasks (e.g. remote
-file transfers through SCP/SFTP, tunnelling over <nowiki>SSH</nowiki>)
-necessary to successfully work remotely.
-===== Connecting to a VLSI machine =====
-All IP addresses of the VLSI machines are visible from within the INFN computing networks,
-as well as from university computers. UNIX/Linux and Mac operating systems provide an <nowiki>SSH</nowiki>
-client out of the box which comes with the **[[http://www.openssh.org/|OpenSSH]]** package, simply run the
-''ssh'' command from any terminal application.
-To remotely access your VLSI machine open a terminal and type
-<code>
-ssh -X username@eltxxxx.to.infn.it
-</code>
-\\
-The first time you connected you should retrive a warning message in the form
-<code>
-The authenticity of host <hostname (IP address)> can't be established.
-RSA key fingerprint is <key>.
-Are you sure you want to continue connecting (yes/no)?
-</code>
-\\
-This is required by the ''ssh'' client to add the machine to the list of known hosts.
-Simply enter ''yes'' and press the ''Return'' key. This stuff is required just once.
-Since the VLSI tools extensively use graphical interfaces you must also
-enable the **X forwarding** with the ''-X'' option passed to the ''ssh'' command.
-This is required to open graphical windows remotely. If you are using a Mac computer
-use ''ssh -Y'' indeed, because Mac's operating systems are stricter about X forwarding
-compared to Linux. The ''-Y'' option enables a //trusted X forwarding// and will allow
-you to work without any problem. If you want to connect from a Windows computer indeed,
-please refer to
-[[vlsi:computing_remote#remote_connections_from_windows|Remote connections from Windows]]
-istructions.
-Be aware that X forwarding needs specific UNIX configurations and permissions to be set
-on the remote machine you want to access (e.g. ''~/.Xauthority'' file).
-Since these setups are not under your control, if the first time you connected you face
-any problems with X forwarding due to permission issues,
-please contact the VLSI system administrator ([[mazza@NOSPAMto.infn.it]], remove NOSPAM in the address).
-[tmp]\\
-You might need to set the ''DISPLAY'' environment variable. This variable must to be set to
-the IP address of your computer followed by a screen address.
-The latter can always be taken to be :0.0.
-<code>
-setenv DISPLAY machine:0.0
-</code>
-\\
-For more details about the usage of the ''ssh'' command type ''man ssh''.
-Further readings and useful links are
-[[http://en.wikibooks.org/wiki/Guide_to_Unix/Explanations/Connecting_to_Remote_Unix]]
-and [[http://plaza.ufl.edu/cmcglone/eel5322/remote_setup.htm]]
-===== Remote connections from Windows =====
-If you are working on a system running Windows (XP, Vista, Seven) some additional
-software is required to deal with remote connections. In particular, you need
-   * an <nowiki>SSH</nowiki> client for Windows to establish the remote connection
-   * an X server for Windows to do X forwarding
-Many different applications (both commercial and free) are available. For a free, simple and
-fast setup a popular choice is to use the **[[http://en.wikipedia.org/wiki/PuTTY|PuTTY]]**
-<nowiki>SSH</nowiki> client and the **[[http://en.wikipedia.org/wiki/Xming|Xming]]** display server.
-Another (actually quite complicated) free option is to use **[[http://www.cygwin.com/|Cygwin]]**.
-PuTTY is a free and open source implementation of Telnet and <nowiki>SSH</nowiki> for Windows
-and UNIX platforms. It provides an ''xterm'' terminal emulator as well. If you don't need
-X forwarding PuTTY is enough to establish the remote connection and then interact with your machine
-through the command line only. It comes as a single executable (putty.exe, ~470 KB) which you can download from
-[[http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html|this page]]. \\
-No installation is required, just save the file somewhere on your system.
-Since the ''C:\windows\'' folder is included in the default Windows search path,
-this is the recommended place, but you can put the executable wherever you like (e.g. Desktop).
-Beside this <nowiki>SSH</nowiki> client, if you want to run a VLSI design tool or any other
-application which requires graphical interfaces you need an X server. Xming
-is a free implementation of the UNIX/Linux X Window System for Windows operating systems.
-Downloads are available at //[[http://www.straightrunning.com/XmingNotes/]]//.
-Although donations must be made to download the latest releases, packages
-listed as //Public Domain// are completely free. \\
-You can download the Xming main installer (Xming-6-9-0-31-setup.exe, 2.2 <nowiki>MB</nowiki>)
-from [[http://sourceforge.net/projects/xming/files/Xming/6.9.0.31/|this direct link]].
-An additional Xming-fonts package (Xming-fonts-7-5-0-47-setup.exe, ~31 <nowiki>MB</nowiki>)
-provides standard core X fonts which are required by the most common UNIX/Linux applications.
-The installation is very fast and easy, simply run the executables and follow the setup
-wizards. We can mention that along with the basic X server (Xming.exe) the
-default Xming full installation includes an enhanced version of PuTTY named PuTTY Link (plink.exe),
-which is a console <nowiki>SSH</nowiki> client similar to the ''ssh'' command on UNIX/Linux and
-Mac operating systems. The Xming-fonts package should be installed in the same directory where
-you installed Xming.
-If you have successfully installed both PuTTY and Xming applications, follow the links
-reported below. They provide step-by-step instructions to setup and make a remote connection.
-   * [[computing_putty_config|Configuring PuTTY]]
-   * [[computing_xming_config|Starting the X server]]
-   * [[computing_putty_connection|Connecting to a remote machine]]
-\\
-Note that
-Use can these instructions to connect through <nowiki>SSH</nowiki>
-to any remote machine (INFN machines, CERN lxplus etc).
-Secure remote file transfers on Windows are possible as well and will be discussed later.
-Useful links:
-   * [[http://www.chiark.greenend.org.uk/~sgtatham/putty|Putty main page]]
-   * [[http://www.chiark.greenend.org.uk/~sgtatham/putty/docs.html|PuTTY official documentation]]
-   * [[http://www.straightrunning.com/XmingNotes/|Xming main page (with documentation)]]
-\\
-Different Web tutorials about the usage of PuTTY and Xming can be foud at:
-   * //[[http://kb.mediatemple.net/questions/1595/Using+SSH+in+PuTTY+%28Windows%29#gs]]//
-   * //[[http://www.math.umn.edu/systems_guide/putty_xwin32.html]]//
-   * //[[http://www.linux.ucla.edu/~phaethon/xming_cadence/xming_cadence.html]]//
-===== Remote desktop access with NX Client =====
-NX Client dovrebbe essere.... piu' veloce! e quindi si dovrebbe riuscire
-ad aprire cadence anche con meno banda! Esiste per Mac, Linux e Windows
-tranquillamente
-As an alternative to a SSH connection, you can try a remote desktop access with the
-NX Client tool. Only a limited number of simultanous connections are allowed, thus
-there is no guarantee that you can access the server at any moment.
-To set a remote desktop access, you must install the NX Client for Windows or NX Client
-for Linux in your computer. In the case of Windows, you must also install the "nxfonts-75dpi"
-   *  [[computing_nxclient_linux|Linux instructions]]
-   *  [[computing_nxclient_windows|Windows instructions]]
-===== Accessing VLSI machines from outside the INFN domain =====
-VLSI machines are visible only from within INFN and university networks.
-You can always verify if your VLSI account is accessible using the ''ping''
-command,
-<code>
-ping username@eltxxxx.to.infn.it
-</code>
-If you retrive an ''unknown host'' issue, then the machine cannot be accessed
-through a simple ''ssh''.
-However, sometimes you might need to access your VLSI account at home or from another insitute.
-To do this, you must first connect through <nowiki>SSH</nowiki> to a machine of the INFN computing cluster.
-If you don't have an INFN computing account read [[computing_accounts|here]] how to obtain it.
-If you already have an INFN UNIX account, available machines for **public login** are
-**bennu.to.infn.it** and **phoinix.to.infn.it**.
-To connect to one of these remote machines, open a terminal and use
-<code>
-ssh [-X] username@bennu.to.infn.it
-</code>
-\\
-or configure a remote connection with PuTTY if you are working on Windows.
-Once logged into an INFN machine, you are back to the //to.infn.it// domain and you can access
-your VLSI machine **eltxxxx.to.infn.it** simply doing a further ''ssh'' at the new command prompt:
-<code>
-ssh [-X] username@eltxxxx.to.infn.it
-</code>
-\\
-A smarter way to do this stuff is called **tunneling** and is described [[vlsi:computing_remote#tips_and_tricks|here]].
-Note that if you want to open graphical windows use the ''-X'' option in both ''ssh'' connections on configure PuTTY
-to enable X forwarding before connecting to INFN central machines.
-Accessing your VLSI machine from outside the INFN domain is useful if you need to access
-Cadence simulation data or other files and documents placed in your local area.  \\
-On the other hand, be aware that //**running Cadence remotely**// on a machine not at the University
-of Turin //**might be specifically forbidden by a license agreement or some other technology restrictions**//!
-In particular, Cadence remote working is forbidden unless the remote machine is within a specified
-distance from the license host machine. Furthermore, the contract for the usage of a particular
-technology may specifically prevent to run Cadence attached to that PDK outside the company site.
-Please, **//run the VLSI tools only at the University of Turin//** or ask the system administrator
-([[mazza@NOSPAMto.infn.it]], remove NOSPAM in the address) if you can remotely access Cadence and
-your technology from other sites.
-===== Remote file transfers =====
-You will be required quite often to deal with file transfers between
-a remote machine and your local system. For instance, you may have a file
-containing some Cadence simulation results located on your remote VLSI machine,
-and you need to download it to your laptop at home for further analysis.
-Since copying files //to// or //from// a remote system is a very common task,
-we provide here more information and how-to's about this topic.
-There are many remote file transfer applications for both UNIX/Linux and Windows
-environments. As for security reasons VLSI and INFN machines allow remote access
-only through <nowiki>SSH</nowiki>, as well only **encrypted file transfers** using
-[[http://en.wikipedia.org/wiki/Secure_copy|Secure Copy (SCP)]] and
-[[http://en.wikipedia.org/wiki/SSH_File_Transfer_Protocol|SSH File Transfer Protocol (SFTP)]]
-programs can be performed.
-===== =====
-\\
-**Secure Copy (SCP)**
-The SCP protocol allows files to be transferred remotely //to//, //from// or //between//
-different hosts through an encrypted connection.
-It uses <nowiki>SSH</nowiki> for data transfer and provides the same authentication
-and the same security level as <nowiki>SSH</nowiki>.
-Similar to ''ssh'', on both UNIX/Linux and Mac operating systems an SCP client comes with
-**[[http://www.openssh.org/|OpenSSH]]** out of the box. Simply run the ''scp'' command
-in a terminal window. The usage of ''scp'' is similar to the well known ''cp'' command
-and follows the same basic syntax,
-<code>
-scp [options] <source> <destination>
-</code>
-\\
-If you want to copy a file **//from a local system to a remote system//** use
-<code>
-cd /path/to/filename/directory/
-scp filename username@hostname:~/path/to/destination
-</code>
-where ''hostname'' is the name of the remote machine on which you want to copy the file (e.g. ''eltxxxx.to.infn.it'').
-You will be prompted to enter your remote login password to complete the operation. Don't forget
-to include the colon '':'' before the destination path. \\
-Giving an absolute destination path is optional, if you use
-<code>
-scp filename username@hostname:
-</code>
-the source file will be copied into your remote home directory ''~/''.\\
-You can also copy multiple files at once, just provide a list
-of them,
-<code>
-scp filename1 filename2 username@hostname:~/path/to/destination
-</code>
-Finally, if you want to copy an entire directory you must use the ''-r'' option
-and make a recursive copy,
-<code>
-scp -r directory username@hostname:~/path/to/destination
-</code>
-\\
-In the same vein you can use ''scp'' to copy files **//from a remote system to a local system//**.\\
-As the source file is located on the remote machine you must
-put the hostname followed by the absolute path of the filename to be copied in front of the local
-destination path,
-<code>
-cd /where/you/want/to/copy/your/file
-scp username@hostname:~/path/to/filename .
-</code>
-The last dot ''.'' in the command means that the destination path is the
-current directory, but you can specify any absolute path. \\
-This is actually the more usual case. As an example, you are working on a machine
-connected to INFN computing networks and you want to download a file from your
-remote VLSI machine or from your INFN UNIX account.
-\\
-The most general syntax of ''scp'' allows copying files **//from a remote system to another remote system//**
-without actually having to log into either of them. This could be useful to share files with
-a colleague. The basic syntax is
-<code>
-scp username1@hostname1:~/path/to/filename username2@hostname2:~/path/to/destination
-</code>
-where ''username1@hostname1'' is the source from which you want to copy the file and
-''username2@hostname2'' is the destination where you want it to be copied.
-At first you will be prompted to enter the login password for ''username1''
-on ''hostname1'' and then a second time for ''username2'' on ''hostname2''.
-To succesfully copying files remotely the remote machines must be visible in the network.
-Thus, you cannot use ''scp'' to directly access files located on your VLSI machine
-from ouside INFN and university networks. You must perform two consecutive ''scp'''s indeed.
-That is, you must first connect through ''ssh'' to an INFN central machine and copying files
-from the VLSI account to your INFN UNIX account,
-<code>
-ssh username@phoinix.to.infn.it
-...
-...
-phoinix.to.infn.it> mkdir tmp
-phoinix.to.infn.it> scp username@eltxxx.to.infn.it:~/path/to/filename ~/tmp/
-</code>
-then you can run a second ''scp'' on your local system (e.g. your laptop at home)
-and retrive the file from the INFN UNIX account.
-<code>
-scp username@phoinix.to.infn.it:~/tmp/filename .
-</code>
-\\
-For more detailed information about the ''scp'' usage and options run ''man scp''
-to access the manual pages. \\
-Further useful link about ''scp'' could be //[[http://www2.imperial.ac.uk/~andy/sysnews/scp/]]//
-and //[[http://kb.iu.edu/data/agye.html]]//.
-\\
-If you are working on a system running Windows (XP, Vista, Seven) you need to install
-an SCP client. both graphical and command line applications.
-A free and easy to use option is **PSCP** (pscp.exe) provided by the PuTTY project.
-It is a command line
-the official documentation
-[[http://the.earth.li/~sgtatham/putty/0.62/htmldoc/Chapter5.html#pscp|Using PSCP to transfer files securely]]
-===== =====
-\\
-\\
-**<nowiki>SSH</nowiki> File Transfer Protocol (SFTP)**
-The main disadvantage of ''scp'' is that if you want to copy a file
-from a remote system to a local system you must know //a priori//
-the exact absolute path of the remote file. An easier way to perform
-this operation is to use an SFTP program.
-On both UNIX/Linux and Mac operating systems **[[http://www.openssh.org/|OpenSSH]]**
-provides an SFTP client out of the box with the ''sftp'' command line application. \\
-Unlike the standard unsecured ''ftp'' client, ''sftp'' performs all the operations
-(commands and data transfers) over an encrypted <nowiki>SSH</nowiki> connection,
-preventing passwords and sensitive information from being transmitted in the clear over a network.
-To start an ''sftp'' session, open a terminal and run the command
-<code>
-sftp username@hostname
-</code>
-where ''hostname'' is the name of the remote machine you want to connect to
-(e.g. eltxxxx.to.infn.it). You will be asked to enter your login password.
-After you have successfully logged into the remote machine,
-''sftp'' moves to your remote home directory. The UNIX prompt
-changes into ''sftp>'' and you can start interacting with the remote system
-using ''sftp'' commands. Besides downloading files, you can move between
-directories and list directory contents, as well as creating and removing
-directories or deleting files. \\
-To get a list of all available commands, type ''help'' at the ''sftp>'' prompt:
-<code>
-sftp> help
-Available commands:
-bye                                Quit sftp
-cd path                            Change remote directory to 'path'
-chgrp grp path                     Change group of file 'path' to 'grp'
-chmod mode path                    Change permissions of file 'path' to 'mode'
-chown own path                     Change owner of file 'path' to 'own'
-df [-hi] [path]                    Display statistics for current directory or
-                                   filesystem containing 'path'
-exit                               Quit sftp
-get [-P] remote-path [local-path]  Download file
-help                               Display this help text
-lcd path                           Change local directory to 'path'
-lls [ls-options [path]]            Display local directory listing
-lmkdir path                        Create local directory
-ln oldpath newpath                 Symlink remote file
-lpwd                               Print local working directory
-ls [-1aflnrSt] [path]              Display remote directory listing
-lumask umask                       Set local umask to 'umask'
-mkdir path                         Create remote directory
-progress                           Toggle display of progress meter
-put [-P] local-path [remote-path]  Upload file
-pwd                                Display remote working directory
-quit                               Quit sftp
-rename oldpath newpath             Rename remote file
-rm path                            Delete remote file
-rmdir path                         Remove remote directory
-symlink oldpath newpath            Symlink remote file
-version                            Show SFTP version
-!command                           Execute 'command' in local shell
-!                                  Escape to local shell
-?                                  Synonym for help
-</code>
-\\
-Commands for navigating remote files and directories (''cd'', ''pwd'', ''mkdir'' etc.)
-follow the same syntax of standard UNIX shell counterparts. The most notable difference
-is that there is a local and a remote version of each command, hence you can interact
-with both the remote and the local systems during an ''sftp'' session.
-In particular, commands prefixed by an ''l'' (''lcd'', ''lpwd'', ''lmkdir'' etc.) idicate
-a local command.
-The ''get'' command allows you to **download files** from the remote machine,
-<code>
-sftp> cd /path/to/filename/directory/
-sftp> get filename [/local/path/where/you/want/to/put/the/file]
-</code>
-If you omit the destination path the file will be put in the local
-directory where you started ''sftp''. You can also download multiple
-files at once by using the ''mget'' command,
-<code>
-sftp> mget filename1 filename2
-</code>
-Since ''sftp'' does not support recursive copies you cannot retrive
-an entire directory and all sub-directories. You can perform a multiple
-download over single files with ''mget'',
-<code>
-sftp> cd /path/to/directory/
-sftp> mget *
-</code>
-or use the ''scp -r'' command instead. Actually, the best work aroud
-when you want to copy a remote directory is to open a standard ''ssh'' session work
-and [[vlsi:unix_basics#working_with_compressed_files|create a compressed archive]]
-of the directory with ''tar'' and ''gzip'' utilities. Then you can download the
-''tar.gz'' file with ''scp'' or ''sftp''.
-You can also **upload files** from the local system to the remote system
-by using ''put'' and ''mput'' commands,
-<code>
-sftp> put /absolute/local/path/to/filename [/remote/path/where/you/want/to/put/the/file]
-</code>
-If you omit the destination path the file will be uploaded in the remote
-current directory.
-\\
-To end the ''sftp'' session, simply type ''exit'', ''quit'' or ''bye'' at the prompt, e.g.
-<code>
-sftp> exit
-</code>
-\\
-For more detailed information about ''sftp'', run ''man scp'' to access the manual pages.
-With PuTTY **PSFTP** (psftp.exe)
-the official documentation
-[[http://the.earth.li/~sgtatham/putty/0.62/htmldoc/Chapter6.html#psftp|Using PSFTP to transfer files securely]]
-Another free and open source application is **Windows Secure Copy (WinSCP)**, which comes
-as a graphical interface tool. is an open source SFTP client for Windows.
-===== =====
-\\
-**Copying large files and directories**
-The best work aroud when you want to copy large files and directories is to
-[[vlsi:unix_basics#working_with_compressed_files|create a compressed archive]]
-with ''tar'' and ''gzip'' utilities,
-<code>
-tar -xczf fileName.tar.gz fileName
-</code>
-Then you can download or upload the ''tar.gz'' file with ''scp'' or ''sftp''.
-===== Web browsing through SSH =====
-Reading scientific literature play a central role in the research and design activity.
-Very often you will need to get **online papers**, largely from
-**[[http://ieeexplore.ieee.org/Xplore/|IEEE]]** or
-**[[http://www.journals.elsevier.com/nuclear-instruments-and-methods-in-physics-research-section-a-accelerators-spectrometers-detectors-and-associated-equipment/|Nuclear Instruments and Methods in Physics Research]]** journals.
-The majority of such documents is available after paying subscribers only and
-cannot be read or downloaded for free. Actually, academic and research institutes
-can purchase subscriptions for their users. That is, you can access online papers
-without any restrictions, because they have been purchased for you by the institute! \\
-Both INFN and University of Turin provide this support, as well as CERN.
-Be aware that at present the subscription with IEEE is available through a CERN
-computing account only.
-You are allowed to read and download papers without any authentication
-only by using a Web browser running on a machine which is
-part of the institute computing networks. Thus, if your are working on a
-machine connected to university or INFN networks you are ok, as well as
-if you are personally at CERN. Otherwise, you cannot access restricted
-pubblications for free from your home or another site, because you don't
-have a username and a password to do it.
-To get rid of this limitation, some further work around is required.
-The quick-and-dirty way is to simply use X forwarding and open the Web browser
-on a remote machine. This would be a pain, because the connection speed would
-be saturated to display the the graphical window of the remote browser!
-The most efficient solution is to create an **<nowiki>SSH</nowiki> tunnel** indeed,
-then configuring your browser to retrive Web data through it (port forwarding).
-Using an  <nowiki>SSH</nowiki> tunnel is significantly faster than trying
-to open a remote session of the browser, because the display rendering
-is done on your local machine and not on the remote one.
-The recommended browser for this purpose is **Firefox**. Step-by-step instructions
-to setup Firefox and create an <nowiki>SSH</nowiki> tunnel on both UNIX/Linux and and Windows
-operating systems can be found [[computing_firefox_tunnelling|here]].
-===== Tips and tricks =====
-//The Secure Shell: The Definitive Guide//
-**Tunnelling**
-Double-hop ssh tunnel (ssh on one machine, then on another)
-Situation: A and B are remote hosts. Local machine can SSH into A, but not B. B ONLY accepts SSH connections from A.
-one SSH from local to A that tunnels from a secondary local port (like 2121) to port 21 on B, and then you can SSH to localhost:2121 and login on B
-Un modo ad esempio e':
-<code>
-ssh -l username -L 7777:eltXXX.to.infn.it:22 zoroastro.to.infn.it cat -
-</code>
-poi la shell rest ain hang, si apre un altro terminale e si mette
-<code>
-ssh -p 7777 username@localhost
-</code>
-e funziona!
-See also //[[http://picobit.wordpress.com/2009/04/26/linux-ssh-forwarding-tunneling-duble-ssh-using-the-console/]]//
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-**Performing <nowiki>SSH</nowiki> login and SCP without password**
-Enter your password every time you want to ssh into you machine is quite annoying!
-''~/.ssh'' directory in your home
-<code>
-cd ~/.ssh
-ssh-keygen [options]
-</code>
-generate a key
-generate a couple of keys, one public and one private with the ''ssh-keygen'' command
-which come with OpenSSH
-You will be prompted to specify a path (the default one ''~/.ssh/id_rsa'' works fine) and a **passphrase** (do not
-use an empty passphrase)
-<code>
-Generating public/private rsa key pair.
-Enter file in which to save the key (/home/username/.ssh/id_rsa): <hit Return to leave default or specify a different path>
-Enter passphrase (empty for no passphrase): <enter a passphrase or leave it empty>
-Enter same passphrase again: <confirm passphrase>
-The key fingerprint is:
-:f8:08:27:20:a1:82:d7:ad:ac:44:30:48:71:17:05 username@local.hostname
-</code>
-After keys has been succesfully generated you have to **copy the public key on the remote system**
-you want to connect to through <nowiki>SSH</nowiki>
-<code>
-ls ~/.ssh
-</code>
-you can use ''scp'' itself,
-<code>
-cd ~/.ssh
-scp id_rsa.pub username@remote.hostname:~/
-</code>
-login on the remote system,
-<code>
-ssh username@remote.hostname
-</code>
-move the ''id.rsa.pub'' as ''~/.ssh/authorized_keys
-<code>
-mv ~/id.rsa.pub ~/.ssh/authorized_keys
-</code>
-E questo e' sufficiente, loggarsi e immettere il passphrase oppure nulla se non la si e'
-inserita.
-[[http://www.thegeekstuff.com/2008/06/perform-ssh-and-scp-without-entering-password-on-openssh/]]
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-Last update: [[ pacher@NOSPAMto.infn.it | Luca Pacher ]] - Mar 11, 2013
-~~NOTOC~~