Attaching network card to a remote server is like cutting a branch sitting on it, If you are on the wrong side you will have a great fall :D

I do it in steps. I create a NIC and add it, then I connect to the new NIC's IP. Then I do whatever work on the first NIC that requires bringing it down. Then I confirm connectivity with the first NIC, then reconnect to it and remove the temporary NIC.

@bahua iam gonna write this down 10 times so i never forget 😉