实验前：

a、先创建root账户 rt

b、测试下网络，方便后续安装所需的工具包

c、查看ip（留个疑问，这里的IP 是172.28.137.241/20与宿主机10.255.50.5有什么关系？）

d、安装所需的工具：net-tools

linux@peggy0223:/$ su root

Password:

root@peggy0223:/# apt install net-tools

Reading package lists... Done

Building dependency tree... Done

Reading state information... Done

The following NEW packages will be installed:

  net-tools

0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.

Need to get 204 kB of archives.

After this operation, 819 kB of additional disk space will be used.

Get:1 http://archive.ubuntu.com/ubuntu jammy/main amd64 net-tools amd64 1.60+git20181103.0eebece-1ubuntu5 [204 kB]

Fetched 204 kB in 2s (111 kB/s)

Selecting previously unselected package net-tools.

(Reading database ... 24208 files and directories currently installed.)

Preparing to unpack .../net-tools_1.60+git20181103.0eebece-1ubuntu5_amd64.deb ...

Unpacking net-tools (1.60+git20181103.0eebece-1ubuntu5) ...

Setting up net-tools (1.60+git20181103.0eebece-1ubuntu5) ...

Processing triggers for man-db (2.10.2-1) ...

然后就可以使用ifconfig -a了