/etc/apt/sources.list 文件中的内容即可/etc/apt/sources.list.d/ubuntu.sources 文件中的内容即可两个文件内容的格式不一样
官方文档： https://help.mirrors.cernet.edu.cn/ubuntu/
/etc/apt/sources.list 文件# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.cernet.edu.cn/ubuntu/ noble main restricted universe multiverse
# deb-src https://mirrors.cernet.edu.cn/ubuntu/ noble main restricted universe multiverse
deb https://mirrors.cernet.edu.cn/ubuntu/ noble-updates main restricted universe multiverse
# deb-src https://mirrors.cernet.edu.cn/ubuntu/ noble-updates main restricted universe multiverse
deb https://mirrors.cernet.edu.cn/ubuntu/ noble-backports main restricted universe multiverse
# deb-src https://mirrors.cernet.edu.cn/ubuntu/ noble-backports main restricted universe multiverse
# 以下安全更新软件源包含了官方源与镜像站配置，如有需要可自行修改注释切换
# deb https://mirrors.cernet.edu.cn/ubuntu/ noble-security main restricted universe multiverse
# # deb-src https://mirrors.cernet.edu.cn/ubuntu/ noble-security main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ noble-security main restricted universe multiverse
# deb-src http://security.ubuntu.com/ubuntu/ noble-security main restricted universe multiverse
# 预发布软件源，不建议启用
# deb https://mirrors.cernet.edu.cn/ubuntu/ noble-proposed main restricted universe multiverse
# # deb-src https://mirrors.cernet.edu.cn/ubuntu/ noble-proposed main restricted universe multiverse
/etc/apt/sources.list.d/ubuntu.sources 文件Types: deb
URIs: https://mirrors.cernet.edu.cn/ubuntu
Suites: noble noble-updates noble-backports
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
# Types: deb-src
# URIs: https://mirrors.cernet.edu.cn/ubuntu
# Suites: noble noble-updates noble-backports
# Components: main restricted universe multiverse
# Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
# 以下安全更新软件源包含了官方源与镜像站配置，如有需要可自行修改注释切换
# Types: deb
# URIs: https://mirrors.cernet.edu.cn/ubuntu
# Suites: noble-security
# Components: main restricted universe multiverse
# Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
# # Types: deb-src
# # URIs: https://mirrors.cernet.edu.cn/ubuntu
# # Suites: noble-security
# # Components: main restricted universe multiverse
# # Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
Types: deb
URIs: http://security.ubuntu.com/ubuntu/
Suites: noble-security
Components: main restricted universe multiverse
Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
# Types: deb-src
# URIs: http://security.ubuntu.com/ubuntu/
# Suites: noble-security
# Components: main restricted universe multiverse
# Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
# 预发布软件源，不建议启用
# Types: deb
# URIs: https://mirrors.cernet.edu.cn/ubuntu
# Suites: noble-proposed
# Components: main restricted universe multiverse
# Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
# # Types: deb-src
# # URIs: https://mirrors.cernet.edu.cn/ubuntu
# # Suites: noble-proposed
# # Components: main restricted universe multiverse
# # Signed-By: /usr/share/keyrings/ubuntu-archive-keyring.gpg
/etc/apt/sources.list 文件# 默认注释了源码镜像以提高 apt update 速度，如有需要可自行取消注释
deb https://mirrors.cernet.edu.cn/ubuntu/ jammy main restricted universe multiverse
# deb-src https://mirrors.cernet.edu.cn/ubuntu/ jammy main restricted universe multiverse
deb https://mirrors.cernet.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
# deb-src https://mirrors.cernet.edu.cn/ubuntu/ jammy-updates main restricted universe multiverse
deb https://mirrors.cernet.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
# deb-src https://mirrors.cernet.edu.cn/ubuntu/ jammy-backports main restricted universe multiverse
# 以下安全更新软件源包含了官方源与镜像站配置，如有需要可自行修改注释切换
# deb https://mirrors.cernet.edu.cn/ubuntu/ jammy-security main restricted universe multiverse
# # deb-src https://mirrors.cernet.edu.cn/ubuntu/ jammy-security main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu/ jammy-security main restricted universe multiverse
# deb-src http://security.ubuntu.com/ubuntu/ jammy-security main restricted universe multiverse
# 预发布软件源，不建议启用
# deb https://mirrors.cernet.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse
# # deb-src https://mirrors.cernet.edu.cn/ubuntu/ jammy-proposed main restricted universe multiverse