The Perl CPAN Testers have been suffering issues accessing their sites, databases and mirrors. According to a posting on the CPAN Testers' blog, the CPAN Testers' server has been being aggressively scanned by "20-30 bots every few seconds" in what they call "a dedicated denial of service attack"; these bots "completely ignore the rules specified in robots.txt".
This "attack" has caused unreliability in the CPAN Testers service. The bots were identified by their IP addresses, including 65.55.207.x, 65.55.107.x and 65.55.106.x, as coming from Microsoft. The administrators of CPAN Testers have now blocked access to their site from these addresses.

Normally, it is expected that bots which scan sites pay attention to the robots.txt file, which tell the bots what is safe to scan and what should be ignored. Search providers like Google also ensure that only one bot is scanning the site at a time.

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