I encountered the following problems while using gitlab
ssh: connect to host gitlab.xxx.com port 22: Connection refused
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.
It was confirmed with the operation and maintenance that it was because someone connected to the same IP multiple times with incorrect passwords, and the gitlab server blocked the IP directly.
It's also possible that someone wants to brute force it.