Date: Fri, 10 Mar 2000 15:02:24 -0500 (EST) From: Omachonu Ogali <oogali@intranova.net> To: Luigi Rizzo <luigi@info.iet.unipi.it> Cc: Mike Heffner <spock@techfour.net>, freebsd-ipfw@FreeBSD.ORG Subject: Re: ipfw doesn't match when src == dest Message-ID: <Pine.BSF.4.10.10003101502050.22637-100000@hydrant.intranova.net> In-Reply-To: <200003101136.MAA75621@info.iet.unipi.it>
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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 <spock@techfour.net> * > > * 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
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