ubuntu默认连接外网，下载速度慢，替换为国内的网络，速度快

    1. #1. 源配置文件是/etc/apt/sources.list文件
    3. # 备份源文件
    4. cp sources.list sources.list.bak
    6. # 编辑源
    7. vim sources.list

    源文件配置如下
    #开头的是注释
    focal是ubuntu版本，替换前边的网址即可

    1. # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
    2. # newer versions of the distribution.
    3. deb http://archive.ubuntu.com/ubuntu/ focal main restricted
    4. # deb-src http://archive.ubuntu.com/ubuntu/ focal main restricted
    6. ## Major bug fix updates produced after the final release of the
    7. ## distribution.
    8. deb http://archive.ubuntu.com/ubuntu/ focal-updates main restricted
    9. # deb-src http://archive.ubuntu.com/ubuntu/ focal-updates main restricted
    11. ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    12. ## team. Also, please note that software in universe WILL NOT receive any
    13. ## review or updates from the Ubuntu security team.
    14. deb http://archive.ubuntu.com/ubuntu/ focal universe
    15. # deb-src http://archive.ubuntu.com/ubuntu/ focal universe
    16. deb http://archive.ubuntu.com/ubuntu/ focal-updates universe
    17. # deb-src http://archive.ubuntu.com/ubuntu/ focal-updates universe
    19. ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
    20. ## team, and may not be under a free licence. Please satisfy yourself as to
    21. ## your rights to use the software. Also, please note that software in
    22. ## multiverse WILL NOT receive any review or updates from the Ubuntu
    23. ## security team.
    24. deb http://archive.ubuntu.com/ubuntu/ focal multiverse
    25. # deb-src http://archive.ubuntu.com/ubuntu/ focal multiverse
    26. deb http://archive.ubuntu.com/ubuntu/ focal-updates multiverse
    27. # deb-src http://archive.ubuntu.com/ubuntu/ focal-updates multiverse
    29. ## N.B. software from this repository may not have been tested as
    30. ## extensively as that contained in the main release, although it includes
    31. ## newer versions of some applications which may provide useful features.
    32. ## Also, please note that software in backports WILL NOT receive any review
    33. ## or updates from the Ubuntu security team.
    34. deb http://archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
    35. # deb-src http://archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
    37. ## Uncomment the following two lines to add software from Canonical's
    38. ## 'partner' repository.
    39. ## This software is not part of Ubuntu, but is offered by Canonical and the
    40. ## respective vendors as a service to Ubuntu users.
    41. # deb http://archive.canonical.com/ubuntu focal partner
    42. # deb-src http://archive.canonical.com/ubuntu focal partner
    44. deb http://security.ubuntu.com/ubuntu/ focal-security main restricted
    45. # deb-src http://security.ubuntu.com/ubuntu/ focal-security main restricted
    46. deb http://security.ubuntu.com/ubuntu/ focal-security universe
    47. # deb-src http://security.ubuntu.com/ubuntu/ focal-security universe
    48. deb http://security.ubuntu.com/ubuntu/ focal-security multiverse
    49. # deb-src http://security.ubuntu.com/ubuntu/ focal-security multiverse

    例如换成阿里云的源

    1. deb http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
    2. deb http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
    3. deb http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
    4. deb http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
    5. deb http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse
    6. deb-src http://mirrors.aliyun.com/ubuntu/ focal main restricted universe multiverse
    7. deb-src http://mirrors.aliyun.com/ubuntu/ focal-security main restricted universe multiverse
    8. deb-src http://mirrors.aliyun.com/ubuntu/ focal-updates main restricted universe multiverse
    9. deb-src http://mirrors.aliyun.com/ubuntu/ focal-proposed main restricted universe multiverse
    10. deb-src http://mirrors.aliyun.com/ubuntu/ focal-backports main restricted universe multiverse