Difference between revisions of "BwForCluster Chemistry Login"

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(Login)
(Create TOTP keys)
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= Create TOTP keys =
 
= Create TOTP keys =
  +
   
 
For better security the log in to JUSTUS 2 requires two factors.
 
For better security the log in to JUSTUS 2 requires two factors.
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password (TOTP) is required as second factor.
 
password (TOTP) is required as second factor.
   
To setup a TOTP for your account, please follow the instructions
+
<b>To setup a TOTP for your account, please follow the instructions
 
that are send to you by email right after registering for
 
that are send to you by email right after registering for
bwForCluster JUSTUS 2.
+
bwForCluster JUSTUS 2.</b>
  +
  +
In general the TOTP consists of a shared secret, that is stored
  +
on our JUSTUS 2 servers <b>and</b> that is imported into a TOTP APP
  +
on your smartphone by scanning a QR-code (quick response code).
  +
  +
With help of this APP you can create a temporary TOTP value (6-digit number),
  +
that must be entered while logging in to JUSUTS 2.
  +
Please be aware that the TOTP value changes every 30 seconds.
  +
So always enter the current 6-digit number as displayed by
  +
the TOTP app.
  +
  +
Another important thing to remember is, that the TOTP value is
  +
valid only once. It is a ONE TIME password. Once entered correctly,
  +
it can no longer be used. For example when you have entered
  +
a correct TOTP value, but a wrong password, the login will ask
  +
you for the TOTP value again. In such cases please wait for
  +
a new TOTP, thus please wait for the next 30 seconds time frame.
  +
  +
Here are some examples for TOTP generator APPs. You can install
  +
one of those APPs in preparation for scanning the QR code
  +
when creating the shared secret.
  +
  +
* Google playstore:
  +
** [https://play.google.com/store/apps/details?id=org.shadowice.flocke.andotp andOTP Authenticator]
  +
** [https://play.google.com/store/apps/details?id=org.fedorahosted.freeotp FreeOTP Authenticator]
  +
** [https://play.google.com/store/apps/details?id=com.beemdevelopment.aegis Aegis Authenticator]
  +
** [https://play.google.com/store/apps/details?id=com.google.android.apps.authenticator2 Google Authenticator]
  +
** [https://play.google.com/store/apps/details?id=com.yubico.yubioath Yubico Authenticator]
  +
  +
* Apple appstore:
  +
** [https://apps.apple.com/us/app/freeotp-authenticator/id872559395 FreeOTP Authenticator]
  +
** [https://apps.apple.com/us/app/google-authenticator/id388497605 Google Authenticator]
  +
** [https://apps.apple.com/us/app/yubico-authenticator/id1476679808 Yubico Authenticator]
  +
  +
*F-Droid store:
  +
** [https://f-droid.org/en/packages/org.shadowice.flocke.andotp/ andOTP Authenticator]
  +
** [https://f-droid.org/en/packages/com.beemdevelopment.aegis/ Aegis Authenticator]
  +
** [https://f-droid.org/en/packages/com.yubico.yubioath/ Yubico Authenticator]
   
 
= Login =
 
= Login =

Revision as of 13:19, 6 July 2020

1 Set service password

Log in to JUSTUS 2 is only possible with a service password. The password of your home organization is not accepted anymore. Therefore please set a service password for JUSTUS 2 by following link "Set password" of section "JUSTUS 2" on the registration server of JUSTUS2 - if you have not done so already.

2 Create TOTP keys

For better security the log in to JUSTUS 2 requires two factors. In addition to your service password, a time-based one-time password (TOTP) is required as second factor.

To setup a TOTP for your account, please follow the instructions that are send to you by email right after registering for bwForCluster JUSTUS 2.

In general the TOTP consists of a shared secret, that is stored on our JUSTUS 2 servers and that is imported into a TOTP APP on your smartphone by scanning a QR-code (quick response code).

With help of this APP you can create a temporary TOTP value (6-digit number), that must be entered while logging in to JUSUTS 2. Please be aware that the TOTP value changes every 30 seconds. So always enter the current 6-digit number as displayed by the TOTP app.

Another important thing to remember is, that the TOTP value is valid only once. It is a ONE TIME password. Once entered correctly, it can no longer be used. For example when you have entered a correct TOTP value, but a wrong password, the login will ask you for the TOTP value again. In such cases please wait for a new TOTP, thus please wait for the next 30 seconds time frame.

Here are some examples for TOTP generator APPs. You can install one of those APPs in preparation for scanning the QR code when creating the shared secret.

3 Login

Prerequisites for login:

  • You have registered your account at the registration server for JUSTUS 2 (to register log in to the registration server of JUSTUS2 and click on "Register" in section of "JUSTUS 2").
  • You have set a service password for JUSTUS 2 (to do so login at the registration server of JUSTUS2 and select "Set Password" in section "JUSTUS 2").
  • You have created a TOTP key and imported that key into a TOTP app on your smartphone (for details see email send by registration server right after account registration).

Thereafter you can access the bwForCluster JUSTUS 2 for Chemistry and Quantum Sciences via ssh. Only the secure shell ssh is allowed for login.

From linux machines, you can log in using

ssh <UserID>@justus2.uni-ulm.de

During log in you must enter the current TOTP token created with help of the TOTP app on your smartphone and your service password.

To run graphical applications, you can use the -X flag to openssh:

ssh -X <UserID>@justus2.uni-ulm.de

For better performance on slow connections you should use e.g. VNC.


The bwForCluster Chemistry in Ulm has four dedicated login nodes. The selection of the login node is done automatically. If you are logging in multiple times, different sessions might run on different login nodes.

The names of the four login nodes are justus2-login01.rz.uni-ulm.de, justus2-login03.rz.uni-ulm.de, justus2-login02.rz.uni-ulm.de, justus2-login04.rz.uni-ulm.de.

These names can be used to access a specific one of the login nodes. In general, you should use justus2.uni-ulm.de to allow us to balance the load over the four login nodes.


3.1 About UserID / Username

<UserID> of the ssh command is a placeholder for your username at your home organization and a prefix denoting your organization. Prefixes and resulting user names are as follows:

Site Prefix Username
Freiburg fr fr_username
Heidelberg hd hd_username
Hohenheim ho ho_username
Karlsruhe ka ka_username
Konstanz kn kn_username
Mannheim ma ma_username
Stuttgart st st_username
Tübingen tu tu_username
Ulm ul ul_username

3.2 Allowed activities on login nodes

The login nodes are the access point to the compute system and its $HOME directory. The login nodes are shared with all the users of the cluster. Therefore, your activities on the login nodes are limited to primarily set up your batch jobs. Your activities may also be:

  • compilation of your program code and
  • short pre- and postprocessing of your batch jobs.

To guarantee usability for all users of the bwForCluster you must not run your compute jobs on the login nodes. Compute jobs must be submitted as Batch Jobs. Any compute job running on the login nodes will be terminated without any notice.

4 Further reading