Document grace period

[richelbilderbeek]

Here we have an RT ticketm from a user:

I've been trying to copy some files from uppmax to my local computer using
scp but the 2 factor authentication is stopping me. [...]
What should I do?

then again from a user:

I am trying to transfer files from Rackham, not Bianca, and that link is in
the stdout message on the terminal when I try to scp. I could do that some
time ago, but not now with this 2-factor authentication. Please, let me
know what I need to do.

Then from Pavlin:

There is a trick. Just use your regular way to ssh to Rackham. It will ask for password then 2FA.
Make sure you managed to login.
This gives you about 5 minutes grace period to login from the same computer to Rackham only with the password.
So start FileZilla or any other tool and login the usual way i.e. only password.

Then me:

How can it be that I never observed the need of such a grace period on Rackham? I just tried doing an scp without logging in first. No grace period needed there; the file was just copied... is it OS related (i.e. I use Linux)?

Then Pavlin:

Scp allows you to enter 2Fa which is a non standard implementation
Gui programs might not know how to handle nonstandard implementation....

And:

https://www.nsc.liu.se/support/2fa/clients/windows/filezilla/ needs interactive login option to work with 2fa

Then me:

Trying this out today, thanks!

Do so 👍

Another link from Pavlin: https://stackoverflow.com/questions/69277631/2fa-with-vs-code-remote-ssh