SSH

Creating a tunnel

That's useful for connecting to a running Jupyter Server somewhere:

ssh -N -f -L localhost:8101:localhost:8101 user@host

Debug messages

ssh -vvv

SSH server is slow

On server, disable DNS:

vim /etc/ssh/sshd_config:

    UseDNS no

SSH client is slow

On client, disable Avahi:

vim /etc/nsswitch.conf

    hosts:          files dnsu

References

• https://jrs-s.net/2017/07/01/slow-ssh-logins/#:~:text=It's%20usually%20DNS.,restart%20ssh%2C%20etc%20as%20appropriate.