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 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).