Date: Fri, 2 Jan 2009 23:44:08 -0600 From: David Kelly <dkelly@hiwaay.net> To: =?ISO-8859-1?Q?Sd=E4vtaker?= <sdavtaker@gmail.com> Cc: freebsd-questions@freebsd.org Subject: Re: Tool for traffic measure? Message-ID: <D0CA6472-99CC-4FF5-A6C8-FFE589E8593F@hiwaay.net> In-Reply-To: <c37d69f60901022121t4d0f8e5dyd43c1eac76478c18@mail.gmail.com> References: <c37d69f60901022121t4d0f8e5dyd43c1eac76478c18@mail.gmail.com>
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On Jan 2, 2009, at 11:21 PM, Sdävtaker wrote: > Hello, > I got a subnet with 5 machines and a cablemodem who provides 5 > public ips > All is conected to a switch. > One of the machines is not ours and we want to check it is not > abuseing our internet link, so we want to know if there is any way to > monitor bandwich usage from one of the other machines in the subnet > with no need to modify the foreing machine config. Something like use > tcpdump in promiscuos mode or something like that, we doesnt matter > the content, we just need a bandwich conssumption meassure. > Thanks for any ideas. Buy a smarter switch and do the traffic counts in the switch. As things stand the switch is isolating all 5 machines from each other, none hear what the others have to say to the cable modem, so there is no way you can sniff the other's traffic. If instead of a switch you had a dumb hub then all machines would hear what all the other machines were saying to each other and the cable modem. Is very hard to buy a dumb hub these days. Is easier to buy a smarter switch. A configurable smart switch can deliver the questionable machine's traffic to both the cable modem and to one of your machines but there is no point unless you want/need to see the contents of the packets. A switch that smart should also be able to count packets and tally total byte counts. If I understand correctly that is all you want. -- David Kelly N4HHE, dkelly@HiWAAY.net ======================================================================== Whom computers would destroy, they must first drive mad.help
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