安装 ubuntu 系统之后，需要安装一些工具软件

以下都是用 root 账号登录操作的；

1、apt-get update

2、apt install net-tools，方便查看 ip 地址（ifconfig）

root@ubuntu:/# apt install net-tools
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following NEW packages will be installed:
  net-tools
0 upgraded, 1 newly installed, 0 to remove and 232 not upgraded.
Need to get 196 kB of archives.
After this operation, 864 kB of additional disk space will be used.
Get:1 http://us.archive.ubuntu.com/ubuntu focal/main amd64 net-tools amd64 1.60+git20180626.aebd88e-1ubuntu1 [196 kB]
Fetched 196 kB in 2s (106 kB/s)                        
Selecting previously unselected package net-tools.
(Reading database ... 178987 files and directories currently installed.)
Preparing to unpack .../net-tools_1.60+git20180626.aebd88e-1ubuntu1_amd64.deb ...
Unpacking net-tools (1.60+git20180626.aebd88e-1ubuntu1) ...
Setting up net-tools (1.60+git20180626.aebd88e-1ubuntu1) ...
Processing triggers for man-db (2.9.1-1) ...
root@ubuntu:/# 

3、安装 ssh 服务，apt-get install openssh-server、apt-get install openssh-client

root@ubuntu:/# 
root@ubuntu:/# ps -aux | grep ssh
mfz         1624  0.0  0.0   6032   456 ?        Ss   17:34   0:00 /usr/bin/ssh-agent /usr/bin/im-launch env GNOME_SHELL_SESSION_MODE=ubuntu /usr/bin/gnome-session --systemd --session=ubuntu
root        4483  0.0  0.0  17664   668 pts/0    S+   17:46   0:00 grep --color=auto ssh
root@ubuntu:/# 
root@ubuntu:/# 
root@ubuntu:/# apt-get install openssh-server
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:


root@ubuntu:/# 
root@ubuntu:/# ps -aux | grep ssh
mfz         1624  0.0  0.0   6032   456 ?        Ss   17:34   0:00 /usr/bin/ssh-agent /usr/bin/im-launch env GNOME_SHELL_SESSION_MODE=ubuntu /usr/bin/gnome-session --systemd --session=ubuntu
root        4902  0.0  0.3  12160  6880 ?        Ss   17:47   0:00 sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups
root        6131  0.0  0.0  17664   660 pts/0    S+   17:47   0:00 grep --color=auto ssh
root@ubuntu:/#

4、安装 vim，apt-get install vim

5、ubuntu 安装/卸载 ssh 服务

安装命令：sudo apt-get install openssh-server

卸载命令：sudo apt-get remove openssh-server

service ssh start 开启ssh服务

service ssh stop 停止ssh服务

service ssh restart 重启ssh服务