redhat linux下配置ssh

1． 检查服务器端的软件包安装
rpm –q openssh-server
2． 启动，停止服务程序
service sshd start/stop/restart
3． 检查客户端的软件包安装
rpm –q openssh-clients

另：启用服务器公钥认证
在服务器编辑文件/etc/ssh/sshd_config，找到语句“PasswordAuthentication yes”，并将语句改为“PasswordAuthentication no”。


1.Log in as the oracle user.
2.If necessary, create the .ssh directory in the oracle user's home directory and set the correct permissions on it:
$ mkdir ~/.ssh
$ chmod 700 ~/.ssh
3.Enter the following commands to generate an RSA key for version 2 of the SSH protocol:
$ /usr/bin/ssh-keygen -t rsa
4.Enter the following commands to generate a DSA key for version 2 of the SSH protocol:
$ /usr/bin/ssh-keygen -t dsa
5.On the local node, determine if you have an authorized key file (~/.ssh/authorized_keys). If the authorized key file already exists, then proceed to step 2. Otherwise, enter the following commands:
$ touch ~/.ssh/authorized_keys
$ cd ~/.ssh
$ ls
You should see the id_dsa.pub and id_rsa.pub keys that you have created.
6.Using SSH, copy the contents of the ~/.ssh/id_rsa.pub and ~/.ssh/id_dsa.pub files to the file ~/.ssh/authorized_keys, and provide the oracle user password as prompted. This process is illustrated in the following syntax example with a two-node cluster, with nodes node1 and node2, where the oracle user path is /home/oracle:
[oracle@node1 .ssh]$ ssh node1 cat /home/oracle/.ssh/id_rsa.pub >> authorized_keys
oracle@node1's password:
[oracle@node1 .ssh]$ ssh node1 cat /home/oracle/.ssh/id_dsa.pub >> authorized_keys
[oracle@node1 .ssh$ ssh node2 cat /home/oracle/.ssh/id_rsa.pub >> authorized_keys
oracle@node2's password:
[oracle@node1 .ssh$ ssh node2 cat /home/oracle/.ssh/id_dsa.pub >>authorized_keys
oracle@node2's password:
7.Use SCP (Secure Copy) or SFTP (Secure FTP) to copy the authorized_keys file to the oracle user .ssh directory on a remote node. The following example is with SCP, on a node called node2, where the oracle user path is /home/oracle:
[oracle@node1 .ssh]scp authorized_keys node2:/home/oracle/.ssh/
8.Repeat this process for each node in the cluster.
9.Change the permissions on the oracle user's /.ssh/authorized_keys file on all cluster nodes:
$ chmod 600 ~/.ssh/authorized_keys
10.Enter the following commands:
$ exec /usr/bin/ssh-agent $SHELL
$ /usr/bin/ssh-add
11.To test the SSH configuration, enter the following commands from the same terminal session, testing the configuration of each cluster node, where nodename1, nodename2, and so on, are the names of nodes in the cluster:
$ ssh nodename1 date
$ ssh nodename2 date