Update failure

A yellow triangle sign appeared on my taskbar. It says 'The update information is outdated. This may be caused by network problems or by a repository that is no longer available. Please update manually by clicking on this icon and then selecting 'Check for updates.' and check if some of the repositories fail.'

I tried to check for new updates and waited for a long time. This is what I got.

"Failed to download repository information

Check your Internet connection.

W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis/Release.gpg Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-security/Release.gpg Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-updates/Release.gpg Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis/main/source/Sources Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis/main/binary-amd64/Packages Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis/main/binary-i386/Packages Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis/main/i18n/Translation-en Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-security/main/source/Sources Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-security/main/binary-amd64/Packages Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-security/main/binary-i386/Packages Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-security/main/i18n/Translation-en Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-updates/main/source/Sources Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-updates/main/binary-amd64/Packages Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-updates/main/binary-i386/Packages Connection failed
, W:Failed to fetch http://in.archive.trisquel.info/trisquel/dists/toutatis-updates/main/i18n/Translation-en Connection failed
, E:Some index files failed to download. They have been ignored, or old ones used instead."

My internet connection is working fine. I didn't have any firewall software turned on when I was trying to check for new updates. What should I do?