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Date:      Sun, 10 Nov 2002 00:05:44 +0200
From:      "Giorgos Keramidas" <keramida@FreeBSD.org>
To:        "Micael Ebbmar" <micke@ebbmar.net>, <freebsd-questions@FreeBSD.org>
Subject:   Re: IPFW2 denies packet although they match ALLOW rule?
Message-ID:  <006b01c2883c$bf360900$42d7cdd4@LocalHost>
References:  <20021109171923.GA41802@h173n2fls21o55>

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Please wrap your posts (everything except for computer output),
below 70-80 columns.  It's very hard to read otherwise :-/

Micael Ebbmar <micke@ebbmar.net> wrote:
: Excuse me if I'm posting to the wrong list, I thought at first that
: freebsd-ipfw should be the correct one, but obviously only
: discussion about the redesign of IPFW should be discussed there.

True.

: A week ago, I made the transition from IPFW to IPFW2 (on my
: 4.7-Stable box), and I thought it would be a good idea to rewrite my
: previous stateless rules to stateful.  After a few days I noticed in
: /var/log security that IPFW once in a while blocks outbound packets
: to my pop servers and a webserver, which I've allowed in a previously
: rule (0310).  I still can pop my mail and browse the web without any
: problems, but I'm stil curious why it denies the packets. Can it be
: that the stateful rule has expired and the interface is
: resending/receiving some old packets? If so, is that normal or an
: indication of a broken NIC?   Or is any of the sysctl variables
: net.inet.ip.fw.* too short? (Haven't touched them yet)

Web clients some times cache connections to web servers, hoping to save
some time from avoiding a reconnect for every GET request.  Could it be
that your clients thinks that a cached connection is still valid long
after the dynamic ipfw rule has expired?

: Log snippet of /var/log/security:
:=20
: Nov  8 00:25:42 grendel /kernel: ipfw: 1000 Deny TCP 213.64.x.x:1938 =
207.174.189.161:80 out via ep1
: Nov  8 00:26:12 grendel /kernel: ipfw: 1000 Deny TCP 213.64.x.x:1940 =
207.174.189.161:80 out via ep1
: Nov  8 00:26:12 grendel /kernel: ipfw: 1000 Deny TCP 213.64.x.x:1938 =
207.174.189.161:80 out via ep1
: [...]
: And my rules look like this:
:=20
: add 0200 reset log tcp from any to any 113
: add 0300 check-state
: add 0305 deny tcp from any to any in established
: add 0310 allow tcp from any to any out setup keep-state
: [...]
: add 0350 allow tcp from me to 10.0.0.6 80 setup keep-state

Doesn't rule 0310 make rule 0350 redundant?

: add 1000 deny log logamount 1000 ip from any to any via ep1


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