Ubuntu下启用ssh

一、SSH（安全外壳协议）。

SSH 为 Secure Shell 的缩写，由 IETF 的网络小组（Network Working Group）所制定；SSH 为建立在应用层基础上的安全协议。SSH 是较可靠，专为远程登录会话和其他网络服务提供安全性的协议。利用 SSH 协议可以有效防止远程管理过程中的信息泄露问题。SSH最初是UNIX系统上的一个程序，后来又迅速扩展到其他操作平台。SSH在正确使用时可弥补网络中的漏洞。SSH客户端适用于多种平台。几乎所有UNIX平台—包括HP-UX、Linux、AIX、Solaris、Digital UNIX、Irix，以及其他平台，都可运行SSH。

二、安装ssh服务。

默认情况下，Ubuntu在最初安装ssh服务时，远程访问是不被允许的。

ms@ubuntu:~$ sudo systemctl status ssh
[sudo] password for ms:
Unit ssh.service could not be found.
ms@ubuntu:~$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00inet 127.0.0.1/8 scope host lovalid_lft forever preferred_lft foreverinet6 ::1/128 scope hostvalid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000link/ether 00:0c:29:9b:91:81 brd ff:ff:ff:ff:ff:ffinet 198.168.1.20/24 brd 198.168.1.255 scope global noprefixroute ens33valid_lft forever preferred_lft foreverinet6 fe80::2de:7698:61b8:808a/64 scope link noprefixroutevalid_lft forever preferred_lft forever
ms@ubuntu:~$
ms@ubuntu:~$ sudo service ssh start
Failed to start ssh.service: Unit ssh.service not found.
ms@ubuntu:~$

使用root或者其它sudo用户身份，安装openssh-server软件包，安装完成后，SSH服务会被自动启动。

sudo apt-get install openssh-server -y

三、查看运行状态。

ms@ubuntu:~$ sudo systemctl status ssh
● ssh.service - OpenBSD Secure Shell serverLoaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)Active: active (running) since Sat 2020-10-31 22:06:28 CST; 20min agoDocs: man:sshd(8)man:sshd_config(5)Main PID: 8037 (sshd)Tasks: 1 (limit: 2285)Memory: 7.2MCGroup: /system.slice/ssh.service└─8037 sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startupsOct 31 22:06:28 ubuntu sshd[8037]: Server listening on :: port 22.
Oct 31 22:06:28 ubuntu systemd[1]: Started OpenBSD Secure Shell server.
Oct 31 22:07:51 ubuntu sshd[9053]: Accepted password for ms from 198.168.1.201 port 57055 ssh2
Oct 31 22:07:51 ubuntu sshd[9053]: pam_unix(sshd:session): session opened for user ms by (uid=0)
Oct 31 22:07:51 ubuntu sshd[9063]: Accepted password for ms from 198.168.1.201 port 57057 ssh2
Oct 31 22:07:51 ubuntu sshd[9063]: pam_unix(sshd:session): session opened for user ms by (uid=0)
Oct 31 22:10:23 ubuntu sshd[9332]: Accepted password for ms from 127.0.0.1 port 44752 ssh2
Oct 31 22:10:23 ubuntu sshd[9332]: pam_unix(sshd:session): session opened for user ms by (uid=0)
Oct 31 22:11:18 ubuntu sshd[9447]: Accepted password for ms from 127.0.0.1 port 44756 ssh2
Oct 31 22:11:18 ubuntu sshd[9447]: pam_unix(sshd:session): session opened for user ms by (uid=0)
ms@ubuntu:~$

四、登录SSH服务器，SSH服务默认端口号为22。

ssh username@ip_address

username为安装了SSH服务机器的用户名，ip_address为安装了SSH服务机器的ip地址。

ms@ubuntu:~$ ssh ms@127.0.0.1
ms@127.0.0.1's password:
Welcome to Ubuntu 20.04.1 LTS (GNU/Linux 5.4.0-52-generic x86_64)* Documentation:  https://help.ubuntu.com* Management:     https://landscape.canonical.com* Support:        https://ubuntu.com/advantage0 updates can be installed immediately.
0 of these updates are security updates.Your Hardware Enablement Stack (HWE) is supported until April 2025.
Last login: Sat Oct 31 22:10:23 2020 from 127.0.0.1
ms@ubuntu:~$

ip地址可通过如下两种方法查询：

ms@ubuntu:~$ ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500inet 198.168.1.20  netmask 255.255.255.0  broadcast 198.168.1.255inet6 fe80::2de:7698:61b8:808a  prefixlen 64  scopeid 0x20<link>ether 00:0c:29:9b:91:81  txqueuelen 1000  (Ethernet)RX packets 12903  bytes 14373423 (14.3 MB)RX errors 0  dropped 0  overruns 0  frame 0TX packets 7003  bytes 577098 (577.0 KB)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536inet 127.0.0.1  netmask 255.0.0.0inet6 ::1  prefixlen 128  scopeid 0x10<host>loop  txqueuelen 1000  (Local Loopback)RX packets 795  bytes 76026 (76.0 KB)RX errors 0  dropped 0  overruns 0  frame 0TX packets 795  bytes 76026 (76.0 KB)TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0ms@ubuntu:~$

ms@ubuntu:~$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00inet 127.0.0.1/8 scope host lovalid_lft forever preferred_lft foreverinet6 ::1/128 scope hostvalid_lft forever preferred_lft forever
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000link/ether 00:0c:29:9b:91:81 brd ff:ff:ff:ff:ff:ffinet 198.168.1.20/24 brd 198.168.1.255 scope global noprefixroute ens33valid_lft forever preferred_lft foreverinet6 fe80::2de:7698:61b8:808a/64 scope link noprefixroutevalid_lft forever preferred_lft forever
ms@ubuntu:~$

当你第一次连接时，你将看到下面的信息：

ms@ubuntu:~$ ssh ms@198.168.1.20
The authenticity of host '198.168.1.20 (198.168.1.20)' can't be established.
ECDSA key fingerprint is SHA256:bY3MYipQnlbdfZzzBZX5bKgWiw2kyNiUHsXNItIXcd4.
Are you sure you want to continue connecting (yes/no/[fingerprint])?

输入yes，并按回车键，会提示输入登录用户的密码：

ms@ubuntu:~$ ssh ms@198.168.1.20
The authenticity of host '198.168.1.20 (198.168.1.20)' can't be established.
ECDSA key fingerprint is SHA256:bY3MYipQnlbdfZzzBZX5bKgWiw2kyNiUHsXNItIXcd4.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '198.168.1.20' (ECDSA) to the list of known hosts.
ms@198.168.1.20's password:

输入密码，并按回车键，就可以登录到ubuntu机器上。

ms@ubuntu:~$ ssh ms@198.168.1.20
The authenticity of host '198.168.1.20 (198.168.1.20)' can't be established.
ECDSA key fingerprint is SHA256:bY3MYipQnlbdfZzzBZX5bKgWiw2kyNiUHsXNItIXcd4.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '198.168.1.20' (ECDSA) to the list of known hosts.
ms@198.168.1.20's password:
Welcome to Ubuntu 20.04.1 LTS (GNU/Linux 5.4.0-52-generic x86_64)* Documentation:  https://help.ubuntu.com* Management:     https://landscape.canonical.com* Support:        https://ubuntu.com/advantage0 updates can be installed immediately.
0 of these updates are security updates.Your Hardware Enablement Stack (HWE) is supported until April 2025.
Last login: Sat Oct 31 22:11:19 2020 from 127.0.0.1
ms@ubuntu:~$

五、若无法登录。

1、确认ssh-server服务是否已启动。

ms@ubuntu:~$ ps -e | grep ssh1130 ?        00:00:00 ssh-agent8037 ?        00:00:00 sshd9335 ?        00:00:00 ssh-agent9815 ?        00:00:00 sshd9817 ?        00:00:00 sshd9881 ?        00:00:00 sshd9946 ?        00:00:00 sshd
ms@ubuntu:~$

若未启动，可以使用如下命令启动SSH服务：

ms@ubuntu:~$ sudo /etc/init.d/ssh start
Starting ssh (via systemctl): ssh.service.
ms@ubuntu:~$

重启SSH服务：

sudo /etc/init.d/ssh restart

停止SSH服务：

sudo /etc/init.d/ssh stop

禁用SSH服务

sudo systemctl disable --now ssh

启动SSH服务

sudo systemctl enable --now ssh

2、让SSH链接通过防火墙。

ms@ubuntu:~$ sudo ufw allow ssh
Rule added
Rule added (v6)
ms@ubuntu:~$

3、为了系统更加安全，减少自动攻击的风险，已更改默认端口号22为其它。在连接到服务器必须指定端口号，不然登录请求会自动发送到主机的22端口。

ms@ubuntu:~$ ssh -p 22 ms@198.168.1.20
ms@198.168.1.20's password:
Welcome to Ubuntu 20.04.1 LTS (GNU/Linux 5.4.0-52-generic x86_64)* Documentation:  https://help.ubuntu.com* Management:     https://landscape.canonical.com* Support:        https://ubuntu.com/advantage0 updates can be installed immediately.
0 of these updates are security updates.Your Hardware Enablement Stack (HWE) is supported until April 2025.
Last login: Sat Oct 31 22:49:09 2020 from 198.168.1.201
ms@ubuntu:~$

Ubuntu下启用ssh相关推荐

Ubuntu下开启SSH服务
网上有很多介绍在Ubuntu下开启SSH服务的文章,但大多数介绍的方法测试后都不太理想,均不能实现远程登录到Ubuntu上,最后分析原因是都没有真正开启ssh-server服务.最终成功的方法如下: ...
linux设置切换窗口特效,Linux_在Ubuntu下启用亮丽的透明玻璃窗口特效，本文将采用图文并茂的形式向 - phpStudy...
在Ubuntu下启用亮丽的透明玻璃窗口特效本文将采用图文并茂的形式向大家演示在 Ubuntu 8.04 (Hardy Heron) 下启用亮丽的透明玻璃窗口特效.以下步骤均在 Thinkpad T6 ...
Ubuntu 下使用SSH 代理
Ubuntu 下使用SSH 代理公司有一个服务器在圣地亚哥,下载速度超快,几个M的,且可以访问youtube,facebook,而从我这访问这个服务器速度也很快 ,scp 也能达到 1M/s . ...
Ubuntu下使用SSH 命令用于登录远程桌面
Ubuntu下使用SSH 命令用于登录远程桌面问题描述工作经常需要在一台电脑(本地主机)上写代码,另一台电脑(服务器,计算力强)上进行训练,两台电脑上都安装的是Ubuntu18.04,为了在loc ...
ubuntu中启用ssh服务
ssh程序分为有客户端程序openssh-client和服务端程序openssh-server.如果需要ssh登陆到别的电脑,需要安装openssh-client,该程序ubuntu是默认安装的.而如 ...
linux服务器启用光口,Ubuntu中启用ssh服务
ssh程序分为有客户端程序openssh-client和服务端程序openssh-server.如果需要ssh登陆到别的电脑,需要安装openssh-client,该程序Ubuntu是默认安装的.而如 ...
Ubuntu 下配置 SSH服务全过程及问题解决
Windows下做Linux开发,装虚拟机里,怎么可以不用SSH呢.有人说,"做Linux开发,还不直接装机器上跑起来了,还挂虚拟机,开SSH--闲的蛋疼了吧",不管怎样,我接触L ...
linux启用root用户,Ubuntu 下启用root账号与修改密码
Ubuntu是一套基于Debian的Linux系统,它追求的是"Just Work",最新的7.10版本发布于2007年10月,不同于其他Linux发行版本,Ubuntu的所有版本 ...
Ubuntu下安装SSH服务
判断是否安装ssh服务,可以通过如下命令进行: $ ssh localhost ssh: connect to host localhost port 22: Connection refused 如 ...

Ubuntu下启用ssh

Ubuntu下启用ssh相关推荐

最新文章

热门文章