sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak

sudo vim  /etc/apt/sources.list

//配置内容如下

deb http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse 

deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse 

deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse 

deb http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse 

deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse 

deb-src http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse 

deb-src http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse 

deb-src http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse 

deb-src http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse 

deb-src http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse focal

sudo apt-get update

sudo apt-get upgrade

打开cmd输入

netplwiz

https://www.iplaysoft.com/tools/chrome/

$ sudo apt install ngrep

$ sudo yum install ngrep

$ sudo dnf install ngrep

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