无法启动到ppa.launchpad.net的连接

Question

$ sudo add-apt-repository ppa:gezakovacs/ppa
 UNetbootin http://unetbootin.github.io/ is a cross-platform utility that can create Live USB systems and can load a variety of system utilities or install various Linux distributions and other operating systems without a CD.

Homepage: http://unetbootin.github.io/
Wiki: http://unetbootin.wiki.sourceforge.net/
Downloads: http://sourceforge.net/project/showfiles.php?group_id=222386
Sourceforge: http://sourceforge.net/projects/unetbootin
Launchpad: http://launchpad.net/unetbootin
 More info: https://launchpad.net/~gezakovacs/+archive/ubuntu/ppa
Press [ENTER] to continue or Ctrl-c to cancel adding it.

Hit:1 http://archive.ubuntu.com/ubuntu eoan InRelease                                 
Get:2 http://archive.ubuntu.com/ubuntu eoan-updates InRelease [97.5 kB]            
Get:3 http://archive.ubuntu.com/ubuntu eoan-backports InRelease [88.8 kB]                                                                                                                                  
Get:4 http://archive.ubuntu.com/ubuntu eoan-security InRelease [97.5 kB]                                                                                                                                   
Get:5 http://archive.ubuntu.com/ubuntu eoan-updates/main amd64 DEP-11 Metadata [73.0 kB]                                                                                                                   
Get:6 http://archive.ubuntu.com/ubuntu eoan-updates/main DEP-11 48x48 Icons [9,953 B]                                                                                                                      
Get:7 http://archive.ubuntu.com/ubuntu eoan-updates/main DEP-11 64x64 Icons [15.1 kB]                                                                                                                      
Get:8 http://archive.ubuntu.com/ubuntu eoan-updates/universe amd64 DEP-11 Metadata [25.9 kB]                                                                                                               
Get:9 http://archive.ubuntu.com/ubuntu eoan-updates/universe DEP-11 48x48 Icons [18.5 kB]                                                                                                                  
Get:10 http://archive.ubuntu.com/ubuntu eoan-updates/universe DEP-11 64x64 Icons [22.9 kB]                                                                                                                 
Get:11 http://archive.ubuntu.com/ubuntu eoan-backports/universe amd64 DEP-11 Metadata [8,068 B]                                                                                                            
Get:12 http://archive.ubuntu.com/ubuntu eoan-security/main amd64 DEP-11 Metadata [204 B]                                                                                                                   
Get:13 http://archive.ubuntu.com/ubuntu eoan-security/universe amd64 DEP-11 Metadata [1,672 B]                                                                                                             
Get:14 http://archive.ubuntu.com/ubuntu eoan-security/universe DEP-11 64x64 Icons [6,242 B]                                                                                                                
Err:15 http://ppa.launchpad.net/gezakovacs/ppa/ubuntu eoan InRelease                                                                                                                                       
  Cannot initiate the connection to ppa.launchpad.net:80 (2001:67c:1560:8008::15). - connect (101: Network is unreachable) Could not connect to ppa.launchpad.net:80 (91.189.95.83), connection timed out
Fetched 465 kB in 31s (15.2 kB/s)                                                                                                                                                                          
Reading package lists... Done
W: Failed to fetch http://ppa.launchpad.net/gezakovacs/ppa/ubuntu/dists/eoan/InRelease  Cannot initiate the connection to ppa.launchpad.net:80 (2001:67c:1560:8008::15). - connect (101: Network is unreachable) Could not connect to ppa.launchpad.net:80 (91.189.95.83), connection timed out
W: Some index files failed to download. They have been ignored, or old ones used instead.

我尝试了论坛上的大多数选项，但都没有奏效。比如此链接。我试着禁用IPV6，但没有用，我试图将服务器从主服务器更改为国家服务器(在软件更新应用程序中)。

Answer 1

这完全是由于学院/大学提供的互联网连接。他们阻止了几件事。我在家也试过同样的方法，一点问题都没有。