I can't update my ubuntu 12.04. I tried it from terminal, update manager and also from the synaptic package manager. The error is
W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/precise-backports/universe/i18n/Translation-en_IN Unable to connect to 172.20.0.100:8080: W: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/precise-backports/universe/i18n/Translation-en Unable to connect to 172.20.0.100:8080: E: Some index files failed to download. They have been ignored, or old ones used instead.