[mrtg] Re: VLANS + Cisco 6509

[Daniel J McDonald]

On Wed, 2003-03-26 at 15:02, Will Saxon wrote:
> We have a 6513 in hybrid mode, and monitoring the vlan interface on the MSFC2 doesn't seem to show 'the whole story.' I could be doing something wrong, though.
> 
> -Will


Right, it only shows the packets that were not cut-through switched.

The only way to get all of the traffic is with netflow, and that's an
whole other breed of cat...

The real question is - why do you care?  Monitoring based on the port is
generally more interesting than on the vlan, unless you want all of the
net-flow data.

> 
> > -----Original Message-----
> > From: Distribution Lists [mailto:dist-lists at e-securenetworks.net]

> > I need some help graphing VLAN traffic on a 6509.
> > From what I have read, the counters that represent VLAN ip traffic is
> > misleading ? Is that correct ?

Not misleading.  Just incomplete.

> > 
> > And if so what alternatives do I have ?

1.  Don't bother monitoring the information as it's pretty much
useless.  There is no "maximum" in cut-through mode, other than the
backplane of the switch (either 32Gb/s or 256Gb/s, depending on whether
the cross-bar feature is set up for your hardware) so you can't use the
information to determine when the resource is going to be exhausted...

2.  set up flow-tools (http://www.splintered.net) and get really
detailed records that tell you everything, but that don't summarize into
tidy graphs.
-- 
Daniel J McDonald, CCIE 2495, CNX
Austin Energy


--
Unsubscribe mailto:mrtg-request at list.ee.ethz.ch?subject=unsubscribe
Archive     http://www.ee.ethz.ch/~slist/mrtg
FAQ         http://faq.mrtg.org    Homepage     http://www.mrtg.org
WebAdmin    http://www.ee.ethz.ch/~slist/lsg2.cgi