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IA migration §2: polish — trim Windows/PuTTY walkthrough, move worker-node section to Compute Nodes, fix links (via update-page on MediaWiki MCP Server)
 
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== Log on using ssh ==
This page explains how to connect to Anunna over SSH. Once you are logged in, see [[Login Nodes]] for what the login nodes are for, and [[Policies and Terms of Use]] for the rules that apply.
One can log in to [[Anunna | Anunna]] using the '''S'''ecure '''Sh'''ell Protocol (SSH) (default port tcp 22). The address of the login server is:
  login.anunna.wur.nl


You will be automatically redirected to the currently valid login server. To log on one has to use an ssh ([http://en.wikipedia.org/wiki/Secure_Shell secure shell]) client. Such client systems are always available from Linux or MacOS systems. For Windows an ssh-client may need to be installed. The most popular ssh-client for Windows is [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY].
== Connecting ==


Note that current access may be restricted to certain IP-ranges. Furthermore, ssh-protocols may be prohibited on systems where port 22 is unavailable due to firewall.
You log in to Anunna using the Secure Shell protocol (SSH) on the default port (TCP 22). The address of the login server is:


The ssh-connection can also be configured to work [[ssh_without_password | without password]], which means that no password needs to be provided at each log-in or secure copy attempt.
login.anunna.wur.nl


  '''IMPORTANT: the Login server can only act as access point and is not to be used for any serious CPU or RAM intensive work.'''
You are automatically redirected to a currently valid login server. An SSH client is built in on Linux and macOS; on Windows you usually install one, such as [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY] or MobaXTerm.
  '''Anything requiring even moderate resources should be [[Using_Slurm  |scheduled using SLURM!]]'''


=== CLI from a Linux/MacOSX terminal ===
Note that access may be restricted to certain IP ranges, and SSH may be blocked where port 22 is closed by a firewall. (For example, WUR FB-IT does not allow port 22 over WiFi to certain systems.)
A Command Line Interface ([http://en.wikipedia.org/wiki/Command-line_interface CLI]) ssh client is available from any Linux or MacOSX terminal. Secure shell (ssh) protocols require port 22 to be open. Should a connection be refused, the firewall settings of the system should be checked. Alternatively, local ICT regulations may prohibit the use of port 22. Wageningen UR FB-ICT for instance does not allow traffic through port 22 over WiFi to certain systems.


<pre>
'''The login server is an access point only — it is not for CPU- or memory-intensive work.''' Anything beyond light, interactive use belongs in a job; see [[Login Nodes]] and [[Scheduler Overview (Slurm)]].
ssh [user name]@login.anunna.wur.nl
</pre>


----
=== Linux and macOS ===


An SSH client is available from any Linux or macOS terminal:


=== MobaXTerm on Windows ===
<syntaxhighlight lang="bash">
The program uses a full Cygwin stack, so commands from Mac and Linux can be used. Though MobaXTerm provides the Mobakeygen extension, which has an intuitive interface and is very convenient.
ssh <username>@login.anunna.wur.nl
</syntaxhighlight>


If the connection is refused, check your firewall settings — SSH needs port 22 open.


==== Connecting to the HPC with MobaXTerm ====
=== Windows ===


Go to '''Session''' => '''SSH''' and under remote host type fill in:
On Windows you connect with an SSH client such as '''MobaXTerm''' or '''PuTTY'''. In either case, set the remote host to <code>login.anunna.wur.nl</code> and enter your username (not your email address) and WUR password. No characters appear while you type your password — this is normal.


<nowiki>login.anunna.wur.nl</nowiki>
For key-based login, generate an SSH key pair with the client's key generator (MobaKeygen in MobaXTerm, or PuTTYgen for PuTTY), protect it with a passphrase, and add the public key to <code>~/.ssh/authorized_keys</code> on Anunna. PuTTY users can hold the key in Pageant so they do not have to type the passphrase each time. See the [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY homepage] for full instructions.


Check the box specify username and type in your username (not your email).
== Logging in without a password ==


Click on OK. Accept the prompt and type in your WUR password and press enter.
You can configure SSH to log in without typing your password each time; see [[ssh_without_password|SSH without password]].
 
'''NOTE:''' No characters will appear on the screen while you are typing your password
 
==== Generating an SSH key pair ====
 
# From the main menu choose '''Tools''' > MobaKeygen SSH Key Generator
# Click on '''Generate''' and move your mouse to generate entropy
# Type in a passphrase for the key
# Save keys with a meaningful name
 
=== PuTTY on Windows ===
Putty is a free, powerful, and widely used SSH client that runs on Windows.
It is extremely useful for those people who have a computer running Windows
on their desk but must remotely connect to a computer running UNIX/Linux.
Putty is one of a set of utilities that all work together to provide
convenient connectivity between Windows and UNIX/Linux environments.
Some of these utilities include:
 
* Putty -- the SSH client
* Pageant -- the authentication agent used with Putty
* Puttygen -- the RSA key generation utility
* Pscp -- the SCP secure file copy utility
 
Depending on your tasks, the above utilities are probably your minimum
set of tools to make convenient connections and file transfers between a
computer running Windows and a computer running UNIX/Linux.
 
==== Putty Configuration ====
 
Putty is able to store the configuration or connection profiles for a
number of remote UNIX/Linix clients.  Each of profile can be created
and later edited by Right-clicking on a putty window header and choosing
"New Session...".  The minimum set of items that need to be configured for
a given connection are:
 
* Session
** Host Name [login.anunna.wur.nl]
** Saved Session name [your name for this connection]
* Terminal
** Keyboard
*** Backspace key -> Control-H
* Connection
** Data
*** Auto-login username [your remote username]
** SSH
*** Auth
**** Private key file for authentication [pathname to your .ppk file]
 
Obviously, there are many other useful things that can be configured and
customized in Putty but the above list should be considered a minimum.
Please note that after making any change to a putty session you must
explicitly save your changes.
 
==== Creating an SSH Key Pair ====
 
Puttygen is the utility used for creating both a .ppk file (private
key) and the public authorized key information.  Briefly, here are
the steps needed to create a key pair:
 
* Run (double-click) the Puttygen application
* Click on "Generate"
* Replace the comment with something meaningful -- maybe your name
* Type in your passphrase (password) twice
* Save the .ppk file in a secure location on your Windows computer
* Use your mouse to copy the public key string then paste it into the ~/.ssh/authorized_keys file on the remote computer
 
Note: The full pathname of this .ppk file is used in the last step of Putty
configuration as described above.
 
==== Using Pageant as an Interface for Putty ====
 
Pageant is a Putty helper program that is used for two main purposes:
 
* Pageant is used to hold the passphrase to your key pair
* Pageant is used as a convenience application to run a Putty session from any of your saved profiles
 
There is no configuration needed in Pageant.  You simply need to
run this program at login.  Any easy way to do this is to create a
shortcut in your startup folder that points to the Pageant executable.
Once this has been done, every time you log in you will see a little
icon of a computer with a hat in your taskbar.  The first step in using
this is to right-click on it and select "Add Key".  Navigate to your
.ppk file and select "Open".  It will prompt you for your passphrase.
At this point your passphrase has been conveniently stored for you so
that when you use Putty to connect to your various remote computers,
you won't have to type in your passphrase over and over again.
The next step is to right-click on the Pageant icon again and select
one of your saved sessions.  If you have done everything correctly
you will be logged right in so that you no longer have to type your
passphrase.
 
== Log on to worker nodes ==
 
In a complete emergency, it is then possible to log on to any of the worker nodes via the login node. Logging on to the worker nodes does not require password authentication, you should therefore not be prompted to provide a password. This is not normally allowed - be aware that running tasks outside of SLURM is prohibited, but so far there has not been any serious abuse of this. This is provided to allow you to get a little more insight in what your job is doing.
 
<pre>
ssh [user name]@[node name]
</pre>
 
For instance:
 
<pre>
ssh dummy001@node049
</pre>
 
Again, it is not permitted to run jobs outside the scheduling software (slurm). So logging on to a worker node is for analyses of running jobs only.


== Connecting to a compute node ==


To open a shell or a direct connection on a compute node where your job is running, see [[Compute Nodes]].


== See also ==
== See also ==
* [[Using _Slurm | Submit jobs with Slurm]]
* [[Login Nodes]]
* [[ssh_without_password | ssh without password]]
* [[Compute Nodes]]
* [[File_transfer | File transfer options]]
* [[Data Transfer Methods]]
* [[ssh_without_password|SSH without password]]
* [[Scheduler Overview (Slurm)]]


== External links ==
== External links ==
* [http://en.wikipedia.org/wiki/Secure_Shell secure shell on Wikipedia]
* [http://en.wikipedia.org/wiki/Secure_Shell Secure Shell on Wikipedia]
* [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY homepage]
* [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY homepage]

Latest revision as of 12:20, 18 June 2026

This page explains how to connect to Anunna over SSH. Once you are logged in, see Login Nodes for what the login nodes are for, and Policies and Terms of Use for the rules that apply.

Connecting

You log in to Anunna using the Secure Shell protocol (SSH) on the default port (TCP 22). The address of the login server is:

login.anunna.wur.nl

You are automatically redirected to a currently valid login server. An SSH client is built in on Linux and macOS; on Windows you usually install one, such as PuTTY or MobaXTerm.

Note that access may be restricted to certain IP ranges, and SSH may be blocked where port 22 is closed by a firewall. (For example, WUR FB-IT does not allow port 22 over WiFi to certain systems.)

The login server is an access point only — it is not for CPU- or memory-intensive work. Anything beyond light, interactive use belongs in a job; see Login Nodes and Scheduler Overview (Slurm).

Linux and macOS

An SSH client is available from any Linux or macOS terminal:

ssh <username>@login.anunna.wur.nl

If the connection is refused, check your firewall settings — SSH needs port 22 open.

Windows

On Windows you connect with an SSH client such as MobaXTerm or PuTTY. In either case, set the remote host to login.anunna.wur.nl and enter your username (not your email address) and WUR password. No characters appear while you type your password — this is normal.

For key-based login, generate an SSH key pair with the client's key generator (MobaKeygen in MobaXTerm, or PuTTYgen for PuTTY), protect it with a passphrase, and add the public key to ~/.ssh/authorized_keys on Anunna. PuTTY users can hold the key in Pageant so they do not have to type the passphrase each time. See the PuTTY homepage for full instructions.

Logging in without a password

You can configure SSH to log in without typing your password each time; see SSH without password.

Connecting to a compute node

To open a shell or a direct connection on a compute node where your job is running, see Compute Nodes.

See also