Seguido este e isto , mas nada mudou. Tentei escolher o melhor servidor em Software e Atualizações, recebi um erro dizendo "Nenhum servidor de download foi encontrado". Minha conexão com a internet está funcionando e posso fazer o ping 8.8.8.8 e também abrir a página do servidor ftp.
A saída do sudo apt-get update:
Err http://extras.ubuntu.com trusty InRelease
Err http://extras.ubuntu.com trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://dl.google.com stable InRelease
Err http://dl.google.com stable Release.gpg
Unable to connect to 127.0.0.1:8080:
Ign https://deb.nodesource.com trusty InRelease
Err http://archive.ubuntu.com trusty InRelease
Err http://archive.ubuntu.com trusty-updates InRelease
Err http://archive.ubuntu.com trusty-backports InRelease
Err http://archive.ubuntu.com trusty-security InRelease
Ign https://deb.nodesource.com trusty Release.gpg
Err http://archive.ubuntu.com trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://archive.ubuntu.com trusty-updates Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://archive.ubuntu.com trusty-backports Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Ign https://deb.nodesource.com trusty Release
Err http://archive.ubuntu.com trusty-security Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty InRelease
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Ign https://deb.nodesource.com trusty/main Sources/DiffIndex
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Err http://ppa.launchpad.net trusty Release.gpg
Unable to connect to 127.0.0.1:8080:
Ign https://deb.nodesource.com trusty/main amd64 Packages/DiffIndex
Ign https://deb.nodesource.com trusty/main i386 Packages/DiffIndex
Ign https://deb.nodesource.com trusty/main Translation-en_IN
Ign https://deb.nodesource.com trusty/main Translation-en
Err https://deb.nodesource.com trusty/main Sources
Failed to connect to 127.0.0.1 port 8080: Connection refused
Err https://deb.nodesource.com trusty/main amd64 Packages
Failed to connect to 127.0.0.1 port 8080: Connection refused
Err https://deb.nodesource.com trusty/main i386 Packages
Failed to connect to 127.0.0.1 port 8080: Connection refused
Reading package lists... Done
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty-updates/InRelease
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty-backports/InRelease
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty-security/InRelease
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/docky-core/ppa/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/gezakovacs/ppa/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/InRelease
W: Failed to fetch http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/n-muench/vlc/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/noobslab/icons/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/noobslab/themes/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/snwh/pulp/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/strukturag/libde265/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/transmissionbt/ppa/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/videolan/master-daily/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/webupd8team/java/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/webupd8team/sublime-text-3/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://ppa.launchpad.net/webupd8team/tor-browser/ubuntu/dists/trusty/InRelease
W: Failed to fetch http://extras.ubuntu.com/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://dl.google.com/linux/chrome/deb/dists/stable/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty-updates/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty-backports/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/trusty-security/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/docky-core/ppa/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/gezakovacs/ppa/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/kubuntu-ppa/backports/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/n-muench/vlc/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/noobslab/icons/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/noobslab/themes/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/snwh/pulp/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/strukturag/libde265/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/transmissionbt/ppa/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/videolan/master-daily/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/webupd8team/java/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/webupd8team/sublime-text-3/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch http://ppa.launchpad.net/webupd8team/tor-browser/ubuntu/dists/trusty/Release.gpg Unable to connect to 127.0.0.1:8080:
W: Failed to fetch https://deb.nodesource.com/node_4.x/dists/trusty/main/source/Sources Failed to connect to 127.0.0.1 port 8080: Connection refused
W: Failed to fetch https://deb.nodesource.com/node_4.x/dists/trusty/main/binary-amd64/Packages Failed to connect to 127.0.0.1 port 8080: Connection refused
W: Failed to fetch https://deb.nodesource.com/node_4.x/dists/trusty/main/binary-i386/Packages Failed to connect to 127.0.0.1 port 8080: Connection refused
W: Some index files failed to download. They have been ignored, or old ones used instead.
W: Duplicate sources.list entry http://dl.google.com/linux/chrome/deb/ stable/main amd64 Packages (/var/lib/apt/lists/dl.google.com_linux_chrome_deb_dists_stable_main_binary-amd64_Packages)
Editar 1: Então, eu queria executar sudo apt-get update e recebi os erros acima para todos os repositórios. Então, verifiquei o servidor que estou usando atualmente para atualizar os repositórios (de Software e Atualizações). Ao escolher o melhor servidor disponível, recebi um erro dizendo "Nenhum servidor de download foi encontrado". Além disso, não estou usando nenhum servidor proxy.
Editar 2: Saída para o host archive.ubuntu.com:
archive.ubuntu.com has address 91.189.88.161
archive.ubuntu.com has address 91.189.88.149
archive.ubuntu.com has address 91.189.88.162
archive.ubuntu.com has address 91.189.88.152
archive.ubuntu.com has IPv6 address 2001:67c:1360:8001::17
archive.ubuntu.com has IPv6 address 2001:67c:1560:8001::11
archive.ubuntu.com has IPv6 address 2001:67c:1360:8001::21
archive.ubuntu.com has IPv6 address 2001:67c:1560:8001::14
Saída para host archive.ubuntu.com 8.8.8.8:
Using domain server:
Name: 8.8.8.8
Address: 8.8.8.8#53
Aliases:
archive.ubuntu.com has address 91.189.88.161
archive.ubuntu.com has address 91.189.88.149
archive.ubuntu.com has address 91.189.88.162
archive.ubuntu.com has address 91.189.88.152
archive.ubuntu.com has IPv6 address 2001:67c:1360:8001::17
archive.ubuntu.com has IPv6 address 2001:67c:1560:8001::11
archive.ubuntu.com has IPv6 address 2001:67c:1360:8001::21
archive.ubuntu.com has IPv6 address 2001:67c:1560:8001::14
Resolvido: Eu tinha usado algum aplicativo que colocou a configuração de proxy para todo o sistema. Remover a seguinte linha para /etc/apt/apt.conf resolveu o problema: Adquirir :: http :: proxy " link "; Obrigada!