I don't see why one should buy special equipment when a code snippet works. I added the snippet while an msnbot indexing swarm was in progress. Apparently modifying robots.txt while a msnbot swarm is in progress doesn't shut them off, and it was msnbot that was effectively causing a DDOS (if unintended) on my server. The wiki it was indexing has a lot of large category pages, and the maximum number of processes in the mysql installation was being overwhelmed. The snippet exits before any queries are launched, so after I added the blocker, I got back access to the wiki and several other sites using the same mysql instance. So it worked for me, because the DDOS was at the level of mysql limits, not at the level of bandwidth. YMMV.

Even if you didn't want to do this at the wiki level, I don't think special equipment is needed. If you know where the DDOS is coming from, you can block at the Apache level, the firewall level, or use throttling scripts. Captcha is to block spambots, but is not effective against DDOS.

JH

===================================== Jim Hu

On Jan 2, 2007, at 7:45 PM, Kasimir Gabert wrote:

Hello Howard,

I am not sure that blocking msnbot from your wiki would accomplish much. You should also block robots in /robots.txt, not in your LocalSettings.php file. If you want to protect against DDoS, you can not do it at a wiki level. You will need to buy special equipment that detects it on a lower level. (Some links: http://www.cisco.com/en/US/netsol/ns615/ networking_solutions_sub_solution.html and http://www.juniper.net/solutions/service_provider/ network_security/ ). If you want to protect against malicious bots, you will have to use something such as captchas to separate the humans from the bots.

I hope that this helps, Kasimir Gabert

On 1/2/07, Jim Hu jimhu@tamu.edu wrote:

...

This may be a bit extreme, but I added this to my LocalSettings.php

$agent= " " . $_SERVER['HTTP_USER_AGENT']; if ( strpos($agent,"msnbot") ) { exit; }

found the snippet via Googling.

Jim Hu

On Jan 2, 2007, at 6:31 PM, howard chen wrote:

...

Hello,

Can share something abt in these area?

Thanks. _______________________________________________ Wikitech-l mailing list Wikitech-l@wikimedia.org http://mail.wikipedia.org/mailman/listinfo/wikitech-l

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