no supported authentication methods available (server sent publickey gssapi-keyex gssapi-with-mic)라고 하면서 SSH 접속이 안될경우 ssh 수정# vi /etc/ssh/sshd_config# PasswordAuthentication yes# ChallengeResponseAuthentication yes를# 없애서PasswordAuthentication yesChallengeResponseAuthentication yes# service sshd restart하면 된다.