You can tell the ssh client to ignore the ssh config file by using the “-F” option and specifying an empty or non-existent config file. For example:
ssh -F /dev/null user@host
This tells ssh to use an empty config file instead of the default one located at ~/.ssh/config
ssh -F /path/to/nonexistent/config user@host
This tells ssh to use a config file that does not exist instead of the default one located at ~/.ssh/config