Err http://archive.canonical.com natty InRelease
Err http://security.ubuntu.com oneiric-security InRelease
Err http://extras.ubuntu.com natty InRelease
Err http://security.ubuntu.com oneiric-security Release.gpg
Temporary failure resolving ‘security.ubuntu.com’
Err http://archive.canonical.com natty Release.gpg
Temporary failure resolving ‘archive.canonical.com’
Err http://extras.ubuntu.com natty Release.gpg
Temporary failure resolving ‘extras.ubuntu.com’
Err http://gb.archive.ubuntu.com oneiric InRelease
Err http://gb.archive.ubuntu.com oneiric-updates InRelease
Err http://gb.archive.ubuntu.com natty-backports InRelease
Err http://gb.archive.ubuntu.com oneiric Release.gpg
Temporary failure resolving ‘gb.archive.ubuntu.com’
Err http://gb.archive.ubuntu.com oneiric-updates Release.gpg
Temporary failure resolving ‘gb.archive.ubuntu.com’
Err http://gb.archive.ubuntu.com natty-backports Release.gpg
Temporary failure resolving ‘gb.archive.ubuntu.com’
Reading package lists... Done
W: Failed to fetch …我意识到有很多“apt-get update: failure to fetch”问题（我通读了我能找到的所有内容），但我目前的情况是 12.04 独有的，它会影响所有来源；不仅仅是启动板。此外，我在欧洲和美国尝试了几种不同的服务器以及“主服务器”（无论在哪里），它们都产生相同的结果：我无法连接到任何软件源。
此外，我相当肯定这个问题源于我今天早上执行的从 11.10->12.04 的升级，因为更新之前就起作用了。
更新管理器的更新工作正常，我可以从软件中心下载一些东西（嘟嘟嘟）而不会发生任何事故，这让我觉得我可以连接到 Ubuntu 服务器的一些子集（但是，其他几个 Ubuntu 服务器——比如额外的——并且某些规范服务器被列为“无法连接”）。
这是来自的输出sudo apt-get update：
sudo apt-get update
Ign http://ftp.u-picardie.fr precise InRelease
Ign http://archive.canonical.com precise InRelease
Ign http://ftp.u-picardie.fr precise-updates InRelease
Ign http://ftp.u-picardie.fr precise-backports InRelease
Err http://ftp.u-picardie.fr precise-security InRelease
Err http://ftp.u-picardie.fr precise Release.gpg
Unable to connect to ftp.u-picardie.fr:http:
Err http://ftp.u-picardie.fr precise-updates Release.gpg
Unable to connect to ftp.u-picardie.fr:http:
Err http://ftp.u-picardie.fr precise-backports Release.gpg
Unable to connect to ftp.u-picardie.fr:http:
Err http://ftp.u-picardie.fr precise-security Release.gpg
Unable to connect to ftp.u-picardie.fr:http:
Hit …运行时sudo apt-get update出现以下错误：
Err archive.ubuntu.com quantal InRelease
Err archive.ubuntu.com quantal-updates InRelease
Err archive.ubuntu.com quantal-backports InRelease
Err archive.ubuntu.com quantal-security InRelease
Err archive.ubuntu.com quantal Release.gpg
Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
Err archive.ubuntu.com quantal-updates Release.gpg
Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
Err archive.ubuntu.com quantal-backports Release.gpg
Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
Err archive.ubuntu.com quantal-security Release.gpg
Unable to connect to archive.ubuntu.com:http: [IP: 91.189.92.177 80]
Reading package lists... Done
W: Failed to fetch archive.ubuntu.com/ubuntu/dists/quantal/InRelease
W: Failed …当我输入时，sudo apt-get update我得到这个：
mohd-arafat-hossain@TUD:~$ sudo apt-get update
[sudo] password for mohd-arafat-hossain:
Ign http://bd.archive.ubuntu.com precise InRelease
Ign http://bd.archive.ubuntu.com precise-updates InRelease
Ign http://bd.archive.ubuntu.com precise-backports InRelease
Ign http://bd.archive.ubuntu.com precise Release.gpg
Ign http://bd.archive.ubuntu.com precise-updates Release.gpg
Ign http://bd.archive.ubuntu.com precise-backports Release.gpg
Ign http://bd.archive.ubuntu.com precise Release
Ign http://bd.archive.ubuntu.com precise-updates Release
Ign http://bd.archive.ubuntu.com precise-backports Release
Ign http://extras.ubuntu.com precise InRelease
Ign http://ppa.launchpad.net precise InRelease
Hit http://extras.ubuntu.com precise Release.gpg
Hit http://ppa.launchpad.net precise Release.gpg
Hit http://extras.ubuntu.com precise Release
Hit http://ppa.launchpad.net precise Release
Hit http://extras.ubuntu.com precise/main Sources
Hit http://bd.archive.ubuntu.com precise/main …好的，所以我在这方面很新，所以我可能没有给你正确数量的信息，但我希望这足以帮助我。
我正在运行 Ubuntu 14.10LTS（甚至认为我的 /etc/apt/source.list 说了一些关于 13.10 的内容）并且我只是打算得到这个“404 not found”和“failed to fetch”，我试过这样做sudo apt-get dist-upgrade，sudo sed -i -e 's/archive.ubuntu.com\|security.ubuntu.com/old-releases.ubuntu.com/g' /etc/apt/sources.list grep -E 'archive.ubuntu.com|security.ubuntu.com' /etc/apt/sources.list.d/*
但他们没有没用，见鬼，我认为最后两件事让事情变得更糟。
terminal read out
Ign cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1) saucy InRelease
Ign cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1) saucy Release.gpg
Ign cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1) saucy Release
Err cdrom://Ubuntu 13.10 _Saucy Salamander_ - Release amd64 (20131016.1) saucy/main amd64 Packages
Please use apt-cdrom to make …