SSH configuration for CARC systems

CARC Team Blog
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In addition setting up SSH keys, you can also modify your SSH configuration to minimize disconnect and login issues for CARC systems. Your SSH configuration is probably located at ~/.ssh/config, depending on your OS or SSH program.

Add something like the following to the configuration file:

Host *.usc.edu
  IdentityFile ~/.ssh/id_ed25519
  ServerAliveInterval 30
  ServerAliveCountMax 4
  ControlMaster auto
  ControlPath ~/.ssh/%r@%h:%p
  ControlPersist 300s

The ServerAlive options help avoid disconnects from CARC servers, such as from bad wifi connections. After an initial login, the ControlMaster options enable multiple sessions over a single connection to allow additional logins without having to enter a password and submit Duo 2FA again, like after a disconnect (up to 300s).

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