I was getting a bit peeved with getting intermittent messages about 'hash sum mismatch' etc. when trying to do sudo apt-get update
Ign http://dl.google.com stable/main Translation-en Fetched 17.1 MB in 9s (1,736 kB/s) W: Failed to fetch bzip2:/var/lib/apt/lists/partial/192.168.1.1:3142_ftp.iinet.net.au_debian_debian_dists_testing_main_binary-amd64_Packages Hash Sum mismatch W: Failed to fetch bzip2:/var/lib/apt/lists/partial/192.168.1.1:3142_ftp.iinet.net.au_debian_debian_dists_testing_contrib_binary-amd64_Packages Hash Sum mismatch W: Failed to fetch bzip2:/var/lib/apt/lists/partial/192.168.1.1:3142_ftp.iinet.net.au_debian_debian_dists_testing_non-free_binary-amd64_Packages Hash Sum mismatch W: Failed to fetch bzip2:/var/lib/apt/lists/partial/192.168.1.1:3142_ftp.iinet.net.au_debian_debian_dists_testing_contrib_i18n_Translation-en Hash Sum mismatch W: Failed to fetch bzip2:/var/lib/apt/lists/partial/192.168.1.1:3142_ftp.iinet.net.au_debian_debian_dists_testing_main_i18n_Translation-en Hash Sum mismatch W: Failed to fetch bzip2:/var/lib/apt/lists/partial/192.168.1.1:3142_ftp.iinet.net.au_debian_debian_dists_testing_non-free_i18n_Translation-en Hash Sum mismatch E: Some index files failed to download. They have been ignored, or old ones used instead.
So I took action:
sudo rm -rf /var/cache/apt-cacher-ng/*
sudo apt-get update Get:1 http://192.168.1.1 testing InRelease [190 kB] Err http://192.168.1.1 testing InRelease Ign http://192.168.1.1 stable InRelease Get:2 http://192.168.1.1 stable Release.gpg [1,672 B] .. Fetched 7,004 kB in 7s (965 kB/s) Reading package lists... Done W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://192.168.1.1 testing InRelease: File /var/lib/apt/lists/partial/192.168.1.1:3142_ftp.iinet.net.au_debian_debian_dists_testing_InRelease doesn't start with a clearsigned message W: Failed to fetch http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/dists/testing/InReleaseso I
sudo apt-get install debian-keyring
which didn't solve anything
Edit you /etc/apt/sources.list and replace all instances of testing with wheezy, e.g.
deb http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/ wheezy main contrib non-free deb http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/ stable main contrib non-free
I don't know if this has to do with the transition towards freezing wheezy, but basically, if you're having problems like that, have a look at what's actually on the mirror you're using. In my case I had a look at ftp://ftp.iinet.net.au/debian/debian/dists/ and found no 'testing' directory.
It also took care of these related messages on a different node:
Fetched 7,493 kB in 8s (885 kB/s) W: Failed to fetch http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/dists/testing/contrib/binary-amd64/PackagesIndex MD5Sum mismatch W: Failed to fetch http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/dists/testing/contrib/i18n/Translation-enIndex MD5Sum mismatch W: Failed to fetch http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/dists/testing/non-free/binary-amd64/PackagesIndex MD5Sum mismatch W: Failed to fetch http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/dists/testing/non-free/i18n/Translation-enIndex MD5Sum mismatch W: Failed to fetch http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/dists/testing/main/i18n/Translation-enIndex MD5Sum mismatch W: Failed to fetch http://192.168.1.1:3142/ftp.iinet.net.au/debian/debian/dists/testing/main/binary-amd64/PackagesIndex MD5Sum mismatch