我使用的是17.04（全新安装），据我所记得，每次尝试安装任何软件都失败，并显示该错误代码。
我尝试过sudo apt-get update && apt-get upgrade，问题仍然存在。
知道为什么吗？
编辑：使用软件更新程序可以得到以下结果：
编辑：更新的输出
guy@LG-LAPTOP:~$ sudo apt-get update && apt-get upgrade
[sudo] password for guy:
Ign:1 http://il.archive.ubuntu.com/ubuntu zesty InRelease
Ign:2 http://il.archive.ubuntu.com/ubuntu zesty-updates InRelease
Ign:3 http://il.archive.ubuntu.com/ubuntu zesty-backports InRelease
Err:4 http://il.archive.ubuntu.com/ubuntu zesty Release
503 Service Unavailable
Get:5 http://security.ubuntu.com/ubuntu zesty-security InRelease [89.2 kB]
Err:6 http://il.archive.ubuntu.com/ubuntu zesty-updates Release
503 Service Unavailable
Get:7 http://archive.canonical.com/ubuntu zesty InRelease [10.2 kB]
Err:8 http://il.archive.ubuntu.com/ubuntu zesty-backports Release
503 Service Unavailable
Get:9 http://archive.canonical.com/ubuntu zesty/partner Sources [1,416 B]
Get:10 http://archive.canonical.com/ubuntu zesty/partner amd64 Packages [1,616 B]
Get:11 http://archive.canonical.com/ubuntu zesty/partner i386 Packages [1,612 B]
Get:12 http://archive.canonical.com/ubuntu zesty/partner Translation-en [708 B]
Get:13 http://security.ubuntu.com/ubuntu zesty-security/main amd64 DEP-11 Metadata [11.7 kB]
Get:14 http://security.ubuntu.com/ubuntu zesty-security/main DEP-11 64x64 Icons [9,219 B]
Get:15 http://security.ubuntu.com/ubuntu zesty-security/universe amd64 DEP-11 Metadata [14.4 kB]
Get:16 http://security.ubuntu.com/ubuntu zesty-security/universe DEP-11 64x64 Icons [31.0 kB]
Reading package lists... Done
E: The repository 'http://il.archive.ubuntu.com/ubuntu zesty Release' does no longer have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://il.archive.ubuntu.com/ubuntu zesty-updates Release' does no longer have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://il.archive.ubuntu.com/ubuntu zesty-backports Release' does no longer have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
guy@LG-LAPTOP:~$
apt get的输出
guy@LG-LAPTOP:~$ sudo apt-get install putty
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
putty-tools
Suggested packages:
putty-doc
The following NEW packages will be installed:
putty putty-tools
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 661 kB of archives.
After this operation, 2,713 kB of additional disk space will be used.
Do you want to continue? [Y/n]
Err:1 http://il.archive.ubuntu.com/ubuntu zesty/universe amd64 putty-tools amd64 0.67-3
503 Service Unavailable
Err:2 http://il.archive.ubuntu.com/ubuntu zesty/universe amd64 putty amd64 0.67-3
503 Service Unavailable
E: Failed to fetch http://il.archive.ubuntu.com/ubuntu/pool/universe/p/putty/putty-tools_0.67-3_amd64.deb 503 Service Unavailable
E: Failed to fetch http://il.archive.ubuntu.com/ubuntu/pool/universe/p/putty/putty_0.67-3_amd64.deb 503 Service Unavailable
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?
guy@LG-LAPTOP:~$