可用的国内源

由阿里云提供的 Debian 镜像源：

deb https://mirrors.aliyun.com/debian/ bullseye main non-free contrib
deb-src https://mirrors.aliyun.com/debian/ bullseye main non-free contrib
deb https://mirrors.aliyun.com/debian-security/ bullseye-security main
deb-src https://mirrors.aliyun.com/debian-security/ bullseye-security main
deb https://mirrors.aliyun.com/debian/ bullseye-updates main non-free contrib
deb-src https://mirrors.aliyun.com/debian/ bullseye-updates main non-free contrib
deb https://mirrors.aliyun.com/debian/ bullseye-backports main non-free contrib
deb-src https://mirrors.aliyun.com/debian/ bullseye-backports main non-free contrib

由腾讯提供的 Debian 镜像源：

deb https://mirrors.tencent.com/debian/ bullseye main non-free contrib
deb-src https://mirrors.tencent.com/debian/ bullseye main non-free contrib
deb https://mirrors.tencent.com/debian-security/ bullseye-security main
deb-src https://mirrors.tencent.com/debian-security/ bullseye-security main
deb https://mirrors.tencent.com/debian/ bullseye-updates main non-free contrib
deb-src https://mirrors.tencent.com/debian/ bullseye-updates main non-free contrib
deb https://mirrors.tencent.com/debian/ bullseye-backports main non-free contrib
deb-src https://mirrors.tencent.com/debian/ bullseye-backports main non-free contrib

由北京清华大学提供的 Debian 镜像源：

deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye main contrib non-free
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-updates main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-updates main contrib non-free
deb https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-backports main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian/ bullseye-backports main contrib non-free
deb https://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-security main contrib non-free
deb-src https://mirrors.tuna.tsinghua.edu.cn/debian-security bullseye-security main contrib non-free

由中国科学技术大学提供的 Debian 镜像源：

deb http://mirrors.ustc.edu.cn/debian bullseye main contrib non-free
deb-src http://mirrors.ustc.edu.cn/debian bullseye main contrib non-free
deb http://mirrors.ustc.edu.cn/debian bullseye-updates main contrib non-free
deb-src http://mirrors.ustc.edu.cn/debian bullseye-updates main contrib non-free
deb http://mirrors.ustc.edu.cn/debian bullseye-proposed-updates main contrib non-free
deb-src http://mirrors.ustc.edu.cn/debian bullseye-proposed-updates main contrib non-free

由上海交通大学提供的 Debian 镜像源：

deb http://mirrors.sjtu.edu.cn/debian bullseye main contrib non-free
deb-src http://mirrors.sjtu.edu.cn/debian bullseye main contrib non-free
deb http://mirrors.sjtu.edu.cn/debian bullseye-updates main contrib non-free
deb-src http://mirrors.sjtu.edu.cn/debian bullseye-updates main contrib non-free
deb http://mirrors.sjtu.edu.cn/debian bullseye-proposed-updates main contrib non-free
deb-src http://mirrors.sjtu.edu.cn/debian bullseye-proposed-updates main contrib non-free

由北京外国语大学提供的 Debian 镜像源：

deb https://mirrors.bfsu.edu.cn/debian/ bullseye main contrib non-free
deb-src https://mirrors.bfsu.edu.cn/debian/ bullseye main contrib non-free
deb https://mirrors.bfsu.edu.cn/debian/ bullseye-updates main contrib non-free
deb-src https://mirrors.bfsu.edu.cn/debian/ bullseye-updates main contrib non-free
deb https://mirrors.bfsu.edu.cn/debian/ bullseye-backports main contrib non-free
deb-src https://mirrors.bfsu.edu.cn/debian/ bullseye-backports main contrib non-free
deb https://mirrors.bfsu.edu.cn/debian-security bullseye-security main contrib non-free
deb-src https://mirrors.bfsu.edu.cn/debian-security bullseye-security main contrib non-free

由华为提供的 Deiban 镜像源：

deb https://mirrors.huaweicloud.com/debian/ bullseye main non-free contrib
deb-src https://mirrors.huaweicloud.com/debian/ bullseye main non-free contrib
deb https://mirrors.huaweicloud.com/debian-security/ bullseye-security main
deb-src https://mirrors.huaweicloud.com/debian-security/ bullseye-security main
deb https://mirrors.huaweicloud.com/debian/ bullseye-updates main non-free contrib
deb-src https://mirrors.huaweicloud.com/debian/ bullseye-updates main non-free contrib
deb https://mirrors.huaweicloud.com/debian/ bullseye-backports main non-free contrib
deb-src https://mirrors.huaweicloud.com/debian/ bullseye-backports main non-free contrib

由网易提供的 Debian 镜像源：

deb https://mirrors.163.com/debian/ bullseye main non-free contrib
deb-src https://mirrors.163.com/debian/ bullseye main non-free contrib
deb https://mirrors.163.com/debian-security/ bullseye-security main
deb-src https://mirrors.163.com/debian-security/ bullseye-security main
deb https://mirrors.163.com/debian/ bullseye-updates main non-free contrib
deb-src https://mirrors.163.com/debian/ bullseye-updates main non-free contrib
deb https://mirrors.163.com/debian/ bullseye-backports main non-free contrib
deb-src https://mirrors.163.com/debian/ bullseye-backports main non-free contrib

手动更换镜像源

手动更换 Debian 镜像源配置主要分为以下三步：

1. 用熟悉的文本编辑器打开 /etc/apt/sources.list 文件（需要 sudo 权限），或是直接执行 sudo apt edit-sources 命令。
2. 替换文件内容为上面任意一个镜像站的源配置代码并保存。
3. 运行 sudo apt-get update 命令更新软件索引。

命令更换镜像源

使用命令替换镜像源更为快捷。比如在没有更换过数据源的情况下，要使用阿里云的 Debian 镜像源：

sudo sed -i 's/deb.debian.org/mirrors.aliyun.com/g' /etc/apt/sources.list

这样就完成了默认源到阿里云镜像源的配置。接下来同样需要执行一下 sudo apt-get update 命令更新软件索引。

上面这个命令的原理在镜像源的地址上。不同的镜像源通常只是域名有所区别，其他部分大致类似。所以之需要通过 sed 命令来修改 /etc/apt/sources.list 这个源配置文件中的域名地址就足够了。

但这意味着使用这个命令方式修改镜像源的配置时需要格外注意。如果输入的匹配地址或替换地址有误，有可能不会生效，或是导致镜像源异常。遇到这种情况，可以选择上面手动更换镜像源的方式来解决。

我们可以看到使用的是https协议

问题描述

然而修改好配置时，进行sudo apt-get update报错：

Reading package lists... Done
W: https://mirrors.aliyun.com/debian/dists/bullseye/InRelease: No system certificates available. Try installing ca-certificates.
W: https://mirrors.aliyun.com/debian/dists/bullseye-updates/InRelease: No system certificates available. Try installing ca-certificates.
W: Failed to fetch https://mirrors.aliyun.com/debian/dists/bullseye/InRelease  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. 
W: Failed to fetch https://mirrors.aliyun.com/debian/dists/bullseye-updates/InRelease  Certificate verification failed: The certificate is NOT trusted. The certificate issuer is unknown.  Could not handshake: Error in the certificate verification. 
W: Some index files failed to download. They have been ignored, or old ones used instead.

出现安全证书不信任的问题

解决办法

有三种解决办法，使用其一即可。

1. 把https协议换成http协议
2. 先安装certificate库（安装命令为 sudo apt install ca-certificates ），再修改成阿里云的源地址。有一种不配源怎么安装，不安装怎么配源的死锁感😂
3. 使用中科大的源，因为他们在这使用的是http协议。