Bill McGonigle(mcgonigle@medicalmedia.com)@2001.09.18 18:58:42 +0000:
On Tuesday, September 18, 2001, at 06:30 PM, Jake Khuon wrote:
You start to suspect a DDOS port-flood attack. It's certainly causing me to spawn a lot of httpds and occupying a lot of ports.
[...]
On Apache 1.3, this brings the number of httpd processes up to MaxClients, then each one waits 300 seconds (the default timeout) for the connections to time out, at which point the other connections are made, and the cycle continues. A DDOS of this nature would be particularly nasty. One client (happened to be on localhost) tied up the server for 6 minutes this way with the default Apache config.
indeed, that's nasty. the quick fix action would be setting Timeout 5 in the httpd.conf, but this won't really fix the problem and make the objects inaccessible for users with high latency links. source ip based connection rate limiting would perhaps solve the problem. are there any modules available out there to accomplish this task?
Here's what the logfile for these attempts looks like:
127.0.0.1 - - [18/Sep/2001:18:43:06 -0400] "-" 408 -
Doh!
yup, i see them from time to time in some of my servers' logs, but not at that rate jake reported. i cc'ed brian from the apache project, perhaps they got some solution for this... /k --
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