SSH access to astro clusters from outside of UP

• You will need a UP account. You can contact me for account creation. Please provide
  
  
  • First name(s)
  • Last name(s); please indicate your surname(s),
    e.g. by using a double space: Magdalena Carmen Frieda   Kahlo y Calderon
  • Date of birth; please give the date in an unambiguous format, e.g., 1. June 2001 or 01.06.2001
  • Place (CITY!) of birth
  • Gender (male/female/diverse/not specified)
  • Email address
  • optional: academic title, name affix
  • position / relation to UP, e.g. collaboration,
  
  according to the web form UP account (screenshot for illustration)
  
  Account will be automatically deactivated after 1 year if not extended before!
  You will get a reminder email 90 d before expiration by ZIM to your UP EMAIL ADDRESS!
  So, check your UP mailbox regularly, set a forward to your other email address, or put a reminder in your calendar.
  Once the account is deactivated, all data in there are deleted and the email address is blocked for 10 yr.
  
  
• ZIM: eduroam / WLAN @ Uni Potsdam
  
  
• Method 1) VPN access: Please install VPN client (root/admin privileges needed): ZIM VPN
  
  After connecting to the UP network via the VPN client, you can just login to all hosts via SSH, e.g.,
  
    ssh htodt@crater.astro.physik.uni-potsdam.de -Y
  
  Or copying files via scp/rsync:
  
    scp -rpC htodt@crater.subnet.physik.uni-potsdam.de:helge.dir .
  
    rsync -av htodt@crater.physik.uni-potsdam.de:helge.dir/ documents/helge.dir
  
  
• Method 2) SSH Gateway instead of VPN:
  
  
  1. If not already existing on your computer (laptop/desktop at home), create an SSH key pair, using ssh-keygen.
     ZIM supports the following types of keys:
     • RSA-4096: ssh-keygen -t rsa -b 4096
     • ED25519: ssh-keygen -t ed25519
     • ECDSA: ssh-keygen -t ecdsa
  2. The public key (id_rsa.pub, id_ed25519.pub, or id_ecdsa.pub) must be uploaded to the ZIM Account.UP SSH public keys (max. 10 keys)
  3. Make sure that you have enabled using the SSH Gateway on Account.UP SSH-Gateway
  4. Either specify the use of the SSH Gateway (=Jumphost) in the SSH call:
     
     ssh -J UPusername@sshgateway.uni-potsdam.de astrousername@host.subnet.physik.uni-potsdam.de
     
     Where:

     UPusername	username assigned by ZIM	e.g., helge.todt
     astrousername	username within astro cluster domain	e.g., htodt
     host.subnet	hostname and subnetname of the astro cluster	e.g., crater.astro

     So, e.g.,
       ssh -J helge.todt@sshgateway.uni-potsdam.de htodt@crater.astro.physik.uni-potsdam.de
     Anologously for scp:
       scp -J UPusername@sshgateway.uni-potsdam.de astrousername@host.subnet.physik.uni-potsdam.de:file localdir
     And for rsync :
       rsync -a -e 'ssh -o "ProxyCommand ssh -A UPusername@sshgateway.uni-potsdam.de -W %h:%p"' astrousername@host.subnet.physik.uni-potsdam.de:file localdir
     
     
  5. Alternatively, create or edit the file ~/.ssh/config, e.g.:

     
     Host *
     ServerAliveInterval 30
     ServerAliveCountMax 5
     
     Host upgateway
     HostName sshgateway.uni-potsdam.de
     User UPusername
     
     Host hostname
     HostName host.subnet.physik.uni-potsdam.de
     User astrousername
     Protocol 2
     ForwardX11 yes
     ForwardX11Trusted yes
     Proxyjump upgateway
     

     where you have to modify the italic placeholder text (UPusername, host.subnet.physik.uni-potsdam.de, astrousername),
     with hostname being a nickname for the host (e.g., crater instead of crater.astro.physik.uni-potsdam.de)
     
     If successfully edited/created your ~/.ssh/config, you can just write, e.g.
     
       ssh hostname