opensuse and openssh

Software

In a normal openSUSE installation, the openSSH package is already installed. This package consists of the following software:

SSHD

This is the SSH Daemon. This daemon is run on the server side. As a default this program is already installed in openSUSE, but does not start during the boot process. Starting SSHD during boot can be set in Yast2 > System Services (Runlevels). Select “sshd” in the list and click enable.

The default listening port of SSHD is 22. Make sure this port is open in the . For configuration possibilities read ""

SSH

This is the client side of the software. You can use this program to log on to any computer that is running the SSHD. Unless they on eg. host basis, of course.

SCP

SCP is based on RCP. It allows the user to copy files over a secure channel between computers. SCP is non interactive, meaning you will have to know where the file is you want to copy and you will have to make sure the destination path exists. It is a nice way to quickly transfer a single file or a directory (in recursive mode) to an other computer. If you are interested in a more interactive way of accessing, downloading and uploading your files, you probably want to use SFTP. Learn more about

SFTP

SFTP is designed as a replacement for FTP, it is not based on it. SFTP makes it possible to interactively transfer file between computers over a secure and encrypted channel. It is designed to be a replacement of tunneling FTP over and SSH connection, which can be a complicated thing. Learn more about .

一般Linux发行版本，例如Ubuntu和SUSE，都默认安装了OpenSSH工具包。完成系统安装，重新启动后，作为服务端的sshd (SSH Daemon)会作为系统服务之一被启动(注：daemon解释为守护进程)。同时一个SSH工具也安装好了，openSSH程序包的一部分，是远程登录 客户端程序。默认安装路径：

    ssh    -   /usr/bin/ssh        对应的配置文件/etc/ssh/ssh_config
     sshd - /usr/sbin/sshd     对应的配置文件/etc/ssh/sshd_config

我只想使用密码登录方式，所以修改了/etc/ssh/sshd_config文件的PasswordAuthentication参数，该参数默认为 no，意思是不允许通过密码认证登录；所以这里改为 yes，在命令行输入ssh restart后重新启动sshd服务。

这次碰到的问题是，在SUSE登录后，在命令界面使用ssh 192.168.2.101能正常登录，但是在另一台Windows系统上面用putty登录时却显示连接超时，登录失败！putty这边设置没有问题， 那么问题可能出在SUSE系统本身或者两台电脑之间的通信。

使用yast查看sshd服务的状态，在命令行输入yast回车，启动yast界面，选择“System > System Services (Runlevel)”，打开System Services (Runlevel):Services界面，检查sshd状态已经是Enabled。使用功能键Alt + E转到Expert Mode, 观察到当前sshd运行在Runlevel 5, (Full multiuser with network and display manager)，这都没有问题。

到网上查查，最后在一个论坛里有人提到检查firewall，需要关闭firework。于是选择在yast中选择“Security and Users > Firewall”，在Firewall configuration界面将Service Start启动方式修改为Manually，然后执行“Stop Firewall Now”，保存修改！

重新启动sshd，再到Windows下试试，一切正常了！