[mrtg] Regarding getting actual traffic.

[Steve Shipway]

> So it means that for the time being MRTG wont provide me with 
> the thing I want.

To be fair, it actually means the your *switch* will not provide the
information that MRTG needs in order to give you the graphs you want.

In order for you to report on more detail than just the number of bytes
transmitted, you need to have an analysis probe -- eg, an RMAN probe --
on the network device that can analyse the traffic and report byte
counts by source, destination, or protocol.  Switches cannot normally do
this.  People oftem ask for such things as 'a count of all web traffic'
-- ie, all traffic on TCP port 80 -- which has the same issue.

MRTG can graph practically anything provided it is given the data.  MRTG
is a graphing tool, not a network traffic analyser.  Note that all other
similar software has the same issue.  Even something like HP Openview
cannot provide this sort of data without an RMAN probe being available.

Hope this makes it clearer,

Steve

--
Steve Shipway
ITSS, University of Auckland 
(09) 3737 599 x 86487
s.shipway at auckland.ac.nz