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Cleanfeed - Global Bad Hosts


As described on the files page this file is identical in function to bad_hosts except that it is intended to be downloaded from a central resource rather than maintained locally. If you choose not to use it, simply ignore these instructions, your Cleanfeed will work fine without it.

How It Works

The bad_hosts_central file is generated automatically by a process that runs on news.mixmin.net. It scans the logfiles produced by its local Cleanfeed and identifies problem hosts that are generating lots of rejected messages. If a threshold number of rejected messages is crossed in a day, the host gets added to the bad_hosts_central file for a period of time (currently 3 days). If during that period the host continues to exceed the reject threshold, the period of time it stays listed keeps rolling forward.

Downloading the file

The bad_hosts_central file is available via FTP or HTTP from www.mixmin.net/cleanfeed/bad_hosts_central The recommended method for obtaining it is via a cron entry like the following:-
00 06,18 * * * wget -qNP /usr/local/news/cleanfeed/etc http://www.mixmin.net/cleanfeed/bad_hosts_central
Make sure that bad_rate_reload is set at a sensible figure for the server you operate or the downloaded file may not be read by Cleanfeed for a long period of time. Conversely don't set it too low or Cleanfeed will be forever rereading its bad_* files which isn't good for performance.

NNTP-Posting-Host Issue

Some News providers choose to put information other than the posting host in this header. In some instances it's an encrypted or hashed version of the actual posting host which is completely compatible with the process that generates the bad_hosts_central file. In one instance that I'm aware of, a major provider is putting their organisation name in the NNTP-Posting-Host header. This will result in them being frequently being listed as a bad host as every message originating from their service appears to come from a single source. Please don't misuse the headers in this manner!