connlimit with iptable

Support for security such as Firewalls and securing linux
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connlimit with iptable

Postby mario_almeida » 2009/07/02 05:25:37

Hi All,

Can someone tell me how to enable connlimit module for iptable


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Re: connlimit with iptable

Postby pschaff » 2009/07/02 21:48:58

Apparently not easily. From a google on

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connlimit iptables ... 59656.html

Please do the "Required reading" and do not multi-post. Another moderator already removed multiple duplicates of your post.

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Re: connlimit with iptable

Postby thewebhostingdi » 2009/08/16 05:30:21

add -m connlimit --connlimit-above

iptables -m connlimit

other options are set at the following location.


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Re: connlimit with iptable

Postby familyguy » 2009/08/26 15:37:31

Given the complexity of installing a non-standard kernel, can anyone offer advice on achieving similar functionality to connlimit? One of my machines is constantly being beaten up (though it is overengineered enough to take the bogus workload in stride). It's usually a dozen or so IP's simultaneously hitting port 80 scanning for SQL injection opportunities in php scripts. The remote IP will connect hundreds or thousands of times, each time from a different source port. Ideally, I'd like to just pick some arbitrary cutoff (say 30 connections within a minute) and drop subsequent connections after that threshold is met.

Any suggestions?

Edit: found this in the wiki and seasoned to taste (does this look like it will work as expected?):

iptables -A INPUT -p tcp --dport 80 --syn -m limit --limit 1/m --limit-burst 30 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 --syn -j DROP