Uploading-an-SSH-Key.md

@@ -8,8 +8,13 @@ To learn more about SSH, you can check out [wikipedia](https://en.wikipedia.org/
 
 Use your SSH key generation tool of choice, such as `ssh-keygen` [manual](https://www.man7.org/linux/man-pages/man1/ssh-keygen.1.html) or [puttyGen](https://www.puttygen.com/). Make sure to generate a key of sufficient length to make it secure. **To ensure your key cannot be abused, set an appropriately strong password for the private key file.** Without such a password, your credentials are very vulnerable.
 
+Strong passwords may be cumbersome to use in everyday cluster access. Help comes in the form of an `ssh-agent` ([manual](https://www.man7.org/linux/man-pages/man1/ssh-agent.1.html)).
+
 Once you have generated the pair of files, save the private key file in the folder `.ssh` on your user directory (`~/.ssh` on Linux, `/c/users/[username]/.ssh` on Windows). You can save the public key file in the same location, or move it elsewhere.
 
+**Note:** Access to the cluster requires password and second factor on first connection within a certain time frame. If you use an ssh config file (a file in your `.ssh` folder named `config`; for more info query your preferred search engine or start [here](https://linuxhandbook.com/ssh-config-file/)), make sure that for this domain (e.g., `*.hpc.itc.rwth-aachen.de`) you are **not** using the public key as your preferred authentication method (i.e., do **not** set `PreferredAuthentications publickey` for this domain). Doing so will prevent the password request and thus login.
+
+
 # Uploading the Public Key
 
 ![Screenshot of the RegApp main dashboard, showing the main navigation ribbon after expanding it from the 'Index' menu point. The new ribbon has three links: Personal Data, My SSH Pubkeys, and My Tokens.](uploads/aff5310ac84f85793ff1ca5fdd5e56d7/Index_Ribbon.png)