From owner-freebsd-ipfw Fri Mar 10 12: 2:17 2000 Delivered-To: freebsd-ipfw@freebsd.org Received: from hydrant.intranova.net (msb-ts-slip09.UMDNJ.EDU [130.219.28.69]) by hub.freebsd.org (Postfix) with SMTP id 259E237BA4A for ; Fri, 10 Mar 2000 12:02:11 -0800 (PST) (envelope-from oogali@intranova.net) Received: (qmail 22775 invoked from network); 10 Mar 2000 20:02:25 -0000 Received: from hydrant.abuselabs.com (HELO hydrant) (@192.168.0.1) by hydrant.abuselabs.com with SMTP; 10 Mar 2000 20:02:25 -0000 Date: Fri, 10 Mar 2000 15:02:24 -0500 (EST) From: Omachonu Ogali To: Luigi Rizzo Cc: Mike Heffner , freebsd-ipfw@FreeBSD.ORG Subject: Re: ipfw doesn't match when src == dest In-Reply-To: <200003101136.MAA75621@info.iet.unipi.it> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-ipfw@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG I usually run across those fragments when logging IGMP packets. On Fri, 10 Mar 2000, Luigi Rizzo wrote: > > Hello, > > > > When I recently redid my firewall, I wanted to block a strange packet from my > > cablemodem, > > > > Deny P:2 192.168.100.1 192.168.100.1 in via ed1 > > are you sure that the logging code prints the right thing ? > I noticed (from source code analysis) it does strange things with > fragments, it might as well misbehave with short packets etc. > > cheers > luigi > > as you can see, the source equals the destination. When I installed the ipfw > > rule below, it wouldn't match the packet: > > > > 00146 0 0 deny log ip from 192.168.100.1 to 192.168.100.1 via ed1 > > > > But when I change the rule to this: > > > > 00146 0 0 deny log ip from 192.168.100.1 to any via ed1 > > > > it'll match the packet and deny it correctly. > > > > Has anyone else noticed this, or have I got this confused somehow? I'm planning > > to look into it a little further, but just wondered if anyone had any ideas > > offhand. > > > > > > Later, > > > > /**************************************** > > * Mike Heffner * > > * Fredericksburg, VA -- ICQ# 882073 * > > * Sent at: 10-Mar-2000 -- 01:37:17 EST * > > * http://my.ispchannel.com/~mheffner * > > ****************************************/ > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe freebsd-ipfw" in the body of the message > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-ipfw" in the body of the message > -- +-------------------------------------------------------------------------+ | Omachonu Ogali oogali@intranova.net | | Intranova Networking Group http://tribune.intranova.net | | PGP Key ID: 0xBFE60839 | | PGP Fingerprint: C8 51 14 FD 2A 87 53 D1 E3 AA 12 12 01 93 BD 34 | +-------------------------------------------------------------------------+ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-ipfw" in the body of the message