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Date:      Tue, 18 Sep 2007 12:13:57 -0300
From:      Agus <agus.262@gmail.com>
To:        "Erik Osterholm" <freebsd-lists-erik@erikosterholm.org>,  freebsd-questions@freebsd.org
Subject:   Re: How to add rule with pfctl...
Message-ID:  <fda61bb50709180813n236fcde1w1349d5f5c030d893@mail.gmail.com>
In-Reply-To: <20070918031323.GA46854@idoru.cepheid.org>
References:  <fda61bb50709151418r61b0e0b4rd889b517b954fae9@mail.gmail.com> <200709152336.27214.fbsd.questions@rachie.is-a-geek.net> <fda61bb50709170945u3a1fba81t8fa8244dbcfc5baf@mail.gmail.com> <46EEB13C.4020509@kinetix.gr> <fda61bb50709171930l7508b458nca9320f3e3ee9cee@mail.gmail.com> <20070918031323.GA46854@idoru.cepheid.org>

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2007/9/18, Erik Osterholm <freebsd-lists-erik@erikosterholm.org>:
>
> On Mon, Sep 17, 2007 at 11:30:03PM -0300, Agus wrote:
> > Agus wrote:
> > >
> > > 2007/9/15, Mel <fbsd.questions@rachie.is-a-geek.net> <
> fbsd.questions@rachie.is-a-geek.net>:
> > >
> > >  On Saturday 15 September 2007 23:18:17 Agus wrote:
> > >
> > >      I am trying to figure out how to add a firewall rule with
> pfctl...
> > > This is what i'm trying to do...
> > >
> > > I've got SEC that matches certain pattern and takes the IP from that
> and
> > > want to trigger a firewall rule to block that IP....
> > > Then after a couple of hours SEC will trigger the command to un-block
> > >
> > >  the
> > >
> > >  IP...
> > > So what i need is the command to block an IP address from command
> line,
> > >
> > >  not
> > >
> > >  touching any pf.conf....
> > >
> > >  If you don't need to add a rule but an IP, then tables are your
> friend.
> > > Example for /etc/pf.conf:
> > > # Placeholder for spammers table, non-routable network IP.
> > > table <spammers> persist { 192.168.111.111 }
> > > # Block this traffic
> > > block return-rst in log on $ext_if proto tcp from <spammers> port smtp
> > >
> > > Then on the command line:
> > > /sbin/pfctl -t spammers -Tadd ip.from.new.spammer
> > > And to delete:
> > > /sbin/pfctl -t spammers -Tdel ip.from.old.spammer
> > >
> > > --
> > > Mel
> > > _______________________________________________
> > > freebsd-questions@freebsd.org mailing list
> > > http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> > > To unsubscribe, send any mail to "
> freebsd-questions-unsubscribe@freebsd.org"
> > >
> > >      Hi,
> > > I put this on /etc/pf.conf
> > > external_addr="192.168.1.11" which is the address of the only
> interface.
> > > This machine isn't a router.
> > >
> > > block drop in quick on $ext_if inet proto tcp from 192.168.0.1 to
> > > $external_addr port ssh
> > >
> > > but when i try to connect from 192.168.0.1 i connect with no
> problems...this
> > > rule is to block access..
> > > What am i doing wrong..is my first time with pf...
> > >
> > > Thankss...
> > > _______________________________________________
> > > freebsd-questions@freebsd.org mailing list
> > > http://lists.freebsd.org/mailman/listinfo/freebsd-questions
> > > To unsubscribe, send any mail to "
> freebsd-questions-unsubscribe@freebsd.org" <
> freebsd-questions-unsubscribe@freebsd.org>
> > >
> > >  2007/9/17, Goltsios Theodore <tgol@kinetix.gr>:
> > Well I think that you mean to add this:
> >
> > ext_if="rl0" # Or whatever your interface is ifconfig helps to find out
> > block drop in quick on $ext_if inet proto tcp from 192.168.0.1 to
> $ext_if
> > port ssh
> >
> > or even:
> > ext_if="rl0"
> > external_addr="192.168.1.11"
> > block drop in quick on $ext_if inet proto tcp from 192.168.0.1 to
> > $external_addr port ssh
> >
> > Think of macros as variables. As long as you don't define them they
> don't
> > exist (are empty).
> >
> >
> >
> > I knowTheodore, i've done it exactly like u put it....first declare
> macros
> > and then the rule....
> > but i couldn't block access to the machine....this rule is supposed to
> block
> > all access to port 22 on the machine coming from 192.168.0.1....but I
> can
> > access from there...
> >
> > i checked pfctl -e
> > pfctl -sa
> >
> > and everything seems to be loaded...
> >
> > Thanks...
>
> Are you sure that you're trying to block only from a specific host?
> The source address shouldn't change, even if you're doing nat.  I
> would assume that you'd want an 'any' keyword there, rather than a
> specific IP address.
>
> Also, you can add hosts to the table automatically based on number of
> connections over a given period of time:
>
> block quick from <blackhole>
> pass on $ext_if inet proto tcp from any to $myip port 22 flags S/SA keep
> state (max-src-conn-rate 5/30, overload <blackhole> flush global)
>
> The first rule blocks hosts from the blackhole table.  The second adds
> hosts to the blackhole table and kills their state if they connect
> more than 5 times in 30 seconds.  This is obviously tunable-- 3/30
> would be 3 connections in 30 seconds, and 8/60 would be 8 connections
> in 60 seconds.
>
> Erik
>


Thanks Erik, That was very helpfull, specially the con-rate...

First i already tried the table rule...but as i wasnt getting any results i
figured i tried first only with a simple rule to see if it works and to make
the question less ambiguous....thats why i posted this rule.... i want to
block from a specific host, which if i make this rule works will be a list
of hosts in a table..and instead of blocking them because of their conn-rate
i will block them by a SEC rule reading from syslog....

and i put that ip to block cause its my router's ip(192.168.0.1) and when i
try to connect from my PC(192.168.0.2) to my server (192.168.1.11) i would
want it to block me..just for testing....but i can't do it....mi router has
NAT so thats why i am blocking its IP and not mi PC...

Hopes it understands....

Thanks a lot...



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