Logging Into login.discoverer.bg (from BG Academic IP Networks) =============================================================== .. toctree:: :maxdepth: 1 :caption: Contents: .. role:: underline :class: underline About ----- .. important:: This document explains how to access the login node of Discoverer HPC without establishing :doc:`vpn`. If your desktop system or SSH jump server is connected to any of **the Bulgarian academic/research networks**, it can be possible to access the Dicoverer HPC login node directly, **without establishing a VPN tunnel to the Discoverer HPC internal network**. That opportunity is provided based on checking the IPv4 address affiliation and **does not cover your home desktop systems**. In case you need SSH access to the Dicoverer HPC login node from your home desktop, then you should either establish :doc:`vpn` or use SSH jump server hosted on one of the Bulgarian academic/research networks. How it works ------------ Instead of connecting to login.discoverer.bg at port 22/tcp (that is the case with :doc:`vpn`), you should point your SSH client to login.bg.discoverer.bg at port 2222/tcp **(mind 'bg' in the host name)**. Installed on login.bg.discoverer.bg is a firewall that restricts the connections to port 2222/tcp. It passes through only SSH connections initiated from IPv4 addresses affiliated to the Bulgarian academic/research network. Prerequisites ------------- To be able to access the login, node you should have: 1. Valid and active Discoverer HPC account (see :doc:`onboarding`) 2. SSH client installed and SSH key-pair generated and stored (see :doc:`ssh`) 3. (optional) SSH jump server, if you want to connect using your home desktop Linux/macOS ----------- Load your private SSH key into the memory (if it is not already loaded there): .. code:: console ssh-add Open a terminal and log into login.bg.discoverer.bg: .. code:: console ssh login.bg.discoverer.bg -l username -p 2222 Windows (PuTTY) --------------- Basic ..... Start your VPN client and establish a VPN tunnel to the Discoverer HPC internal network. See :doc:`vpn`. Before running PuTTY, use Pageant to cache your SSH private key into the memory by following the procedure described in :doc:`ssh_caching_openssh_key`. To run PuTTY go to the seach bar of Windows, type there "putty" (1), and click on the application icon (2): .. image:: _images/putty_00.png In the window of the application, be sure you are in the secion "Session" (1), then in the text field below "Host Name (or IP address)" type login.bg.discoverer.bg (2), be sure the port number is set 2222 (3), select "SSH" as a connection type (4), and press the button "Open" (5): .. image:: _images/putty_01_a.png Upon first time connecting to login.bg.discoverer.bg on the current desktop Windows user profile, PuTTY will rise a warning window message and will display there the key algorithm (1) and the key fingerprint value (2) computed for of the server's SSH key: .. image:: _images/putty_02.png .. warning:: If the reported fingerprint value is not listed in the document :doc:`ssh_key_fingeprint`, do not press "Accept" or "Connect Once" buttons. Press "Cance" and report the incident to the Discoverer HPC support team - see :doc:`help` and wait for their response. Then enter your username and press enter: .. image:: _images/putty_03_a.png In case of successful login one should see the MOTD message, along with the shell environment command line: .. image:: _images/putty_04.png Using a profile of settings ........................... Start your VPN client and establish a VPN tunnel to the Discoverer HPC internal network. See :doc:`vpn`. Before running PuTTY, use Pageant to cache your SSH private key into the memory by following the procedure described in :doc:`ssh_caching_openssh_key`. You can follow the instructions in `Setting up a profile`_ below to create your own PuTTY profile of settings for connecting to login.bg.discoverer.bg. To run PuTTY go to the seach bar of Windows, type there "putty" (1), and click on the application icon (2): .. image:: _images/putty_00.png From the list of profiles, select "login.bg.discoverer.bg" by clicking twice on it: .. image:: _images/putty_08_a.png and PuTTY will initiate SSH connection to login.bg.discoverer.bg. In case of successful login one should see the MOTD message, along with the shell environment command line: .. image:: _images/putty_04.png Setting up a profile .................... Run PuTTY by typing "putty" (1) in the Windows search bar, and click on the application icon (2): .. image:: _images/putty_00.png In the left plane of the PuTTY window, click on "Connection" (1), mark there (if they are not) "Enable Naggle's algorithm" and "Enable TCP keepalives" (2), and provide the number of seconds between two consequent keepalive messages (3), which for the example below is 60 seconds: .. image:: _images/putty_06.png In "Data" (1) provide your Discoverer HPC username (2): .. image:: _images/putty_05.png so as it can be automatically provided every time you log into login.bg.discoverer.bg. Finally, to save the profile settings, click on "Session", type login.bg.discoverer.bg in the text field below "Host Name (and IP address)" (2), specify "2222" as port number (3), select "SSH" as connection type (4), type login.bg.discoverer.bg below "Saved Sessions" (5), and finally press "Save" to save the profile of settings under that name (6): .. image:: _images/putty_07_a.png Getting help ............ See :doc:`help`