Access with SSH

amplitUDE

The login process using ssh is done with a 2FA-authentication (password + OTP-token). Thereby, the general OTP-token provided together with the UDE-account is used. Details see Information on two-factor authentication

For the access to amplitUDE the jump host login.hpc.uni-due.de is provided which provides load balancing across the frontend/login nodes of the cluster.

We recommend adding

Host login-ampl
    Hostname amplitude
    User [USERNAME]
    XAuthLocation [X11BINPATH]/xauth
    ProxyJump login.hpc.uni-due.de
    ForwardX11 no
    ForwardX11Trusted no

Host login.hpc.uni-due.de
    Hostname login.hpc.uni-due.de
    User [USERNAME]
    XAuthLocation [X11BINPATH]/xauth
    ForwardX11 no
    ForwardX11Trusted no

to your $HOME/.ssh/config on your local machine. Change [USERNAME] to your UDE account name (i.e. your uni-kennung) in lowercase, and replace [X11BINPATH] with the absolute path to the xauth program.

With this configuration setup you can subsequently open an interactive session on amplitUDE with

ssh login-ampl

you will be asked for your password and OTP-token to login.

If you need to a run graphical application, the -X option should be used, which enables X11 forwarding with X11 SECURITY extension. The complete command is

ssh -X login-ampl

You can check whether this worked correctly by running

echo $DISPLAY

on amplitUDE. This should print something like

localhost:11.0

Note that to run graphical applications on amplitUDE you need to have an X-Windows server installed on your local machine. See the X-Windows section for details.

Also note that when you forward the DISPLAY variable this does create some cyber security risks. The remote machine or another machine pretending to be the remote machine can see your screen content, monitor keystrokes, and even potentially control your desktop. To reduce these risks

  • Only enable X11 forwarding for machines where you really need it and

  • Use untrusted X11 forwarding (ssh -X rather than ssh -Y)

Note that “untrusted” doesn’t mean that you use an untrustworthy connection. “Untrusted” here means you assume that the machine you are connecting to should not be trusted. This leaves some protections turned on.

If you’d rather avoid changing your $HOME/.ssh/config file then you can use

ssh -t USERNAME@login.hpc.uni-due.de ssh amplitude

as an alternative. Here you need to replace USERNAME with your account name.