Kvm启动ubuntu虚拟机无法ssh

1. ssh：Connection refused

1） ssh 120.0.0.11 Connection refused

root@node2:/opt/zq# ssh ubuntu@120.0.0.11ssh: connect to host 120.0.0.11 port 22: Connection refused

2. ubuntu虚拟机安装openssh-server

1） apt-get安装，如果提示无法安装，找不到源，那么apt-get update

apt-get install openssh-server      

2） 如果，更新源还是不可以，则修改源路径：

vi /etc/apt/sources.list

修改如下：

deb http://mirrors.163.com/ubuntu/ trusty main restricted universe multiversedeb http://cn.archive.ubuntu.com/ubuntu/ trusty main restricted universe multiversedeb http://cn.archive.ubuntu.com/ubuntu/ trusty-updates main restricted universe multiversedeb http://cn.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse

3. WARNING: IDENTIFICATION HAS CHANGED!

1） ssh远程无法登陆，提示验证。首先确保登录用户为root权限。

root@node2:/opt/zq# ssh 120.0.0.11@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!Someone could be eavesdropping on you right now (man-in-the-middle attack)!It is also possible that a host key has just been changed.The fingerprint for the ECDSA key sent by the remote host isa1:d1:fe:08:87:87:e0:0f:64:d1:fa:0b:7a:28:09:78.Please contact your system administrator.Add correct host key in /root/.ssh/known_hosts to get rid of this message.Offending ECDSA key in /root/.ssh/known_hosts:37  remove with: ssh-keygen -f "/root/.ssh/known_hosts" -R 120.0.0.11ECDSA host key for 120.0.0.11 has changed and you have requested strict checking.Host key verification failed.

2） 开启ssh远程权限

 vi /etc/ssh/ssh_config 

ubuntu版本不同该文件有所区别：
http://blog.csdn.net/qiqishuang/article/details/51547884
修改如下：

Host *#   ForwardAgent no#   ForwardX11 no#   ForwardX11Trusted yes#   RhostsRSAAuthentication no#   RSAAuthentication yes   PasswordAuthentication no#   HostbasedAuthentication no#   GSSAPIAuthentication no#   GSSAPIDelegateCredentials no#   GSSAPIKeyExchange no#   GSSAPITrustDNS no#   BatchMode no#   CheckHostIP yes#   AddressFamily any#   ConnectTimeout 0#   StrictHostKeyChecking ask#   IdentityFile ~/.ssh/identity#   IdentityFile ~/.ssh/id_rsa#   IdentityFile ~/.ssh/id_dsa   Port 22#   Protocol 2,1#   Cipher 3des#   Ciphers aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc#   MACs hmac-md5,hmac-sha1,[e-mail],hmac-ripemd160#   EscapeChar ~#   Tunnel no#   TunnelDevice any:any#   PermitLocalCommand no#   VisualHostKey no#   ProxyCommand ssh -q -W %h:%p gateway.example.com#   RekeyLimit 1G 1h    SendEnv LANG LC_*    HashKnownHosts yes    GSSAPIAuthentication yes    GSSAPIDelegateCredentials no

3) 依然无法登陆，则有以下几种解决方案：

• Just delete the known_hosts file If you have only used one ssh server

mv /root/.ssh/known_hosts /tmp

• Add correct host key in /home/user/.ssh/known_hosts
  http://www.cyberciti.biz/faq/warning-remote-host-identification-has-changed-error-and-solution/

4. ssh正确登陆姿势

1） 不正确姿势：ssh 120.0.0.11

root@node2:/opt/zq# ssh 120.0.0.11The authenticity of host '120.0.0.11 (120.0.0.11)' can't be established.ECDSA key fingerprint is a1:d1:fe:08:87:87:e0:0f:64:d1:fa:0b:7a:28:09:78.Are you sure you want to continue connecting (yes/no)? yesWarning: Permanently added '120.0.0.11' (ECDSA) to the list of known hosts.root@120.0.0.11's password: Permission denied, please try again.root@120.0.0.11's password: Permission denied, please try again.root@120.0.0.11's password: Permission denied (publickey,password).

2） 正确姿势：ssh ubuntu@120.0.0.11

root@node2:/opt/zq# ssh ubuntu@120.0.0.11ubuntu@120.0.0.11's password: Welcome to Ubuntu 14.04.3 LTS (GNU/Linux 3.19.0-25-generic x86_64) * Documentation:  https://help.ubuntu.com/  System information as of Tue May 31 02:59:19 EDT 2016  System load: 0.22              Memory usage: 3%   Processes:       83  Usage of /:  5.0% of 17.34GB   Swap usage:   0%   Users logged in: 0  Graph this data and manage this system at:    https://landscape.canonical.com/0 packages can be updated.0 updates are security updates.Last login: Tue May 31 02:59:19 2016