Mailing List Archive: Block an IP if there is number of connection within a time limit ??

Block an IP if there is number of connection within a time limit ??

Jun 26, 2007, 10:12 PM

Post #1 of 3 (1850 views)

Dear List,

I do have a Exim mail server with IPTABLES and TCP WRAPPER as firewall.
Yesterday I had noticed that,there is continuous smpt connection from an
IP. I would like to block these IP,if there is more than 10 connection
in 30 second. Is this possible using IPTABLES command. If yes,Please
guide me.

Thanks in Advance
--

Re: Block an IP if there is number of connection within a time limit ?? [ In reply to ]

gtaylor at riverviewtech

Jun 26, 2007, 10:18 PM

Post #2 of 3 (1777 views)

Permalink

On 6/27/2007 12:12 AM, Ditro - BipinDas wrote:
> I do have a Exim mail server with IPTABLES and TCP WRAPPER as
> firewall. Yesterday I had noticed that,there is continuous smpt
> connection from an IP. I would like to block these IP,if there is
> more than 10 connection in 30 second. Is this possible using IPTABLES
> command. If yes,Please guide me.

Use the IPTables "recent" match extension to match on newly established
SMTP sessions and reject them if there have been more than 10 in the
last 30 seconds.

Grant. . . .

Re: Block an IP if there is number of connection within a time limit ?? [ In reply to ]

debjuanca at gmail

Jun 27, 2007, 8:55 AM

Post #3 of 3 (1781 views)

Permalink

2007/6/27, Grant Taylor <gtaylor@riverviewtech.net>:
> On 6/27/2007 12:12 AM, Ditro - BipinDas wrote:
> > I do have a Exim mail server with IPTABLES and TCP WRAPPER as
> > firewall. Yesterday I had noticed that,there is continuous smpt
> > connection from an IP. I would like to block these IP,if there is
> > more than 10 connection in 30 second. Is this possible using IPTABLES
> > command. If yes,Please guide me.
>
> Use the IPTables "recent" match extension to match on newly established
> SMTP sessions and reject them if there have been more than 10 in the
> last 30 seconds.

iptables -I INPUT -p tcp --dport 25 -i eth0 -m state --state NEW -m recent \
--update --seconds 30 --hitcount 10 -j DROP

>
>
>
> Grant. . . .
>
>