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Re: OT? Device to limit simultaneous connections per host?

  • From: Howard Hart
  • Date: Wed Aug 17 21:57:01 2005

A simple Linux/IPTables combo can cover the rate limiting to 10 packets/second piece of this.

/sbin/iptables -N HTTP
/sbin/iptables -A HTTP -i eth0 -m limit --limit 10 --limit-burst 1 -j ACCEPT
/sbin/iptables -A HTTP -i eth0 -j DROP

/sbin/iptables -A INPUT -i eth0 -p tcp --destination-port 80 -j HTTP


You'd just need to run it on your Web server.

Someone more creative than me can probably come up with a -p tcp -m state -start ESTABLISHED -j DROP pre-rule in combination with the rules above to to limit the number of connections per client.


David Hubbard wrote:

Hello everyone, I'm curious if anyone knows of a
device that can throttle or limit a remote
host's simultaneous connections or requests per
second for web traffic on a per-IP basis. So I
don't want to say web server X can only have 100
simultaneous connections and 10 requests per second.
I want to say that for any given IP connecting to
web server X, any one IP can have no more than 5 open
connections and should be throttled if it starts
making more than ten requests per second. If it
could even be url-aware in that it could only apply
the rules to specific types of web requests, that
would be even better.

The motivation here is to find a piece of equipment
that can protect compute-intensive, database-driven
websites from overly aggressive proxies, firewalls,
search engines, etc. which like to hammer a given
site with 50+ simultaneous requests against pages
that could potentially need a few seconds of
processing time per request.

I've looked at a Packeteer PacketShaper running
in reverse of what it normally would, trying to
throttle and shape requests against the server
rather than optimizing traffic for a low speed
link like it was designed, but that didn't really
work out as it could not have the policies applied
on a per remote IP basis.

Thanks,

David