Tool for traffic measure?

Sdävtaker sdavtaker at gmail.com
Sat Jan 3 08:03:59 PST 2009


Thanks for the info, i got a linksys SD208:
http://www.linksys.com/servlet/Satellite?c=L_Product_C2&childpagename=US%2FLayout&cid=1123638180923&pagename=Linksys%2FCommon%2FVisitorWrapper&lid=8092322279B03
It got 0 intelligence, right?
Thanks for the replies
Sdav

On Sat, Jan 3, 2009 at 4:00 AM, Kurt Buff <kurt.buff at gmail.com> wrote:
> On Fri, Jan 2, 2009 at 9:21 PM, Sdävtaker <sdavtaker at gmail.com> 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.
>> Sdav
>
> You have several options:
>
> 1) If the switch has some intelligence, you can monitor it to measure
> bandwidth consumption. There are two ways to do this:
>     a) if the switch implements SNMP, you can use mrtg (simple) or
> cacti (not so simple) to graph bandwidth on the switch by port and in
> total
>     b) if the switch can mirror all of the data going across the
> switch to a port on the switch, you can use ntop to graph traffic. It
> only shows the top three bandwidth consumers at any given time, but i)
> it does have very nice graphing, and if the machine you are concerned
> about is consuming more than its fair share it will show, and ii) you
> can use standard bpf filters to capture utilization for just that box.
>
> 2) if you have a spare machine, you can put two NICs in it, and use it
> as a bridge between the switch and the router. This is a bit more
> complicated, but it allows you to implement either option 1a or 1b
> above.
>
> Kurt
>



-- 
Sdävtaker prays to Rikku goddess for a good treasure.


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