ssh -v debug1:Authentications that can continue: publickey,gssapi-keyex,gssapi-with-mic,password debug1:Next authentication method: gssapi-keyex debug1:No valid Key exchange context debug1:Next authentication method: gssapi-with-mic debug1:Unspecified GSS failure.Minor code may provide more information Cannot determine realm for numeric host address debug1:Unspecified GSS failure.Minor code may provide more information Cannot determine realm for numeric host address debug1:Unspecified GSS failure.Minor code may provide more information debug1:Unspecified GSS failure.Minor code may provide more information Cannot determine realm for numeric host address debug1:Next authentication method: publickey debug1:Tryingprivate key:/home/mitchellchu/.ssh/id_rsa debug1:Tryingprivate key:/home/mitchellchu/.ssh/id_dsa debug1:Tryingprivate key:/home/mitchellchu/.ssh/id_ecdsa debug1:Next authentication method: password
可以看出连接顺序GSSAPI，Public_key，password
password方式登陆的话，前面耗费时间过长
解决办法：
禁用GSSAPI，使用Public_key方式登录，弃用password方式
禁用GSSAPI认证有两个方式：客户端和服务端
客户端：
ssh -o GSSAPIAuthentication=no your-server-username@serverIP
手动输入麻烦的话，可以使用Xshell的快速命令功能
服务端：
/etc/ssh/sshd_config
GSSAPIAuthentication no
若卡在SSH2_MSG_SERVICE_ACCEPT received很久，则修改为UseDNS no