Date: Tue, 22 Oct 2002 15:48:13 -0300 (ADT) From: "Marc G. Fournier" <scrappy@hub.org> To: Luigi Rizzo <rizzo@icir.org> Cc: freebsd-net@FreeBSD.ORG Subject: Re: determining "originator/source" of connection ... Message-ID: <20021022154730.K25737-100000@hub.org> In-Reply-To: <20021022113249.C33933@carp.icir.org>
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On Tue, 22 Oct 2002, Luigi Rizzo wrote: > let me understand, you basically want something that puts flow statistics > in the bucket identified by the <dst-ip,dst-port> of the first SYN > packet you see (the assumption being that connections are > initiated by clients towards a well known port, which appears > as dst-port in the first syn packet ? > > Or if you are just happy to aggregate by IP, one solution i often > use is the following (based on dummynet's dynamic pipes): > > # do not expire pipes even if they have no pending traffic > sysctl net.inet.ip.dummynet.expire=0 > > # create separate pipes for src and dst masks > ipfw pipe 20 config mask src-ip 0xffffffff buckets 256 > ipfw pipe 21 config mask dst-ip 0xffffffff buckets 256 > > ipfw add pipe 20 ip from $my_subnet to any > ipfw add pipe 21 ip from any to $my subnet I don't believe I could do this with ipfw ... $my_subnet == 131.162.0.0 :( I fear the machin would strat to smoke, no? :( > > cheers > luigi > > > On Tue, Oct 22, 2002 at 02:47:36PM -0300, Marc G. Fournier wrote: > > > > I've got FreeBSD setup as a firewall to our campus network, and its doing > > a great job of it, but we want to be able log statistics on traffic going > > in and out ... > > > > I have trafd running on the server, with it dumping its data to a > > PostgreSQL database, but for every ~8min "segment", it is logging ~12 000 > > records ... so ~90k/hr, or 2.16 million per day ... > > > > Now, I'm figuring that if I could determine direction of flow (did we > > originate the connection, or did someone off campus originate it), I could > > shrink that greatly, as right now I have stuff like: > > > > 216.158.133.242 80 131.162.158.24 3914 6 2356 4 > > 216.158.133.242 80 131.162.158.24 3915 6 47767 34 > > 216.158.133.242 80 131.162.158.24 3916 6 78962 56 > > 216.158.133.242 80 131.162.158.24 3917 6 330141 224 > > 216.158.133.242 80 131.162.158.24 3918 6 118862 89 > > 216.158.133.242 80 131.162.158.24 3919 6 264139 185 > > 216.158.133.242 80 131.162.158.24 3920 6 259543 179 > > 216.158.133.242 80 131.162.158.24 3921 6 98014 73 > > 216.158.133.242 80 131.162.158.24 3922 6 267772 186 > > 216.158.133.242 80 131.162.158.24 3923 6 148879 109 > > 216.158.133.242 80 131.162.158.24 3924 6 6406 8 > > 216.158.133.242 80 131.162.158.24 3925 6 2486 5 > > 216.158.133.242 80 131.162.158.24 3928 6 109584 75 > > 216.158.133.242 80 131.162.158.24 3929 6 92435 62 > > 216.158.133.242 80 131.162.158.24 3936 6 13059 9 > > 216.158.133.242 80 131.162.158.24 3937 6 22641 17 > > > > where I don't care about the source port, only the dest port ... except, > > in the above, trafd is writing it as 'source port == 80' and 'dest port' > > is arbitray ... > > > > while later in the results, I'll get something like: > > > > 130.94.4.7 40072 131.162.138.193 25 6 2976 10 > > 130.94.4.7 58562 131.162.138.193 25 6 5249 16 > > > > which does make sense (ie. source port -> dest port) ... > > > > is there something that i can do with libpcap that will give me better > > information then trafd does? is there a 'tag' in the IP headers that can > > be used to determine the originator of the connection? > > > > thanks ... > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > with "unsubscribe freebsd-net" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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