What is the known_hosts file?
location ~/.ssh/konwn_hostsin
When the record is linked to the other party, the host key given by the other party will check whether the host key given by the other party is the same as the host key you recorded every time you connect, and perform simple verification.
Today I reinstalled my Tencent Cloud, and the following problems occurred when I connected:
The solution is to first enter ~/.ssh/konwn_hosts of your own computer and delete the host key of the original server. After deleting it, it will be OK to link again.