Pentascanner, analyze lan traffic

Pentascanner, analyze lan traffic

Post by Todd Felml » Fri, 13 Jul 2001 00:48:53



I have an original Pentascanner. It doesn't seem to want to analyze LAN
traffic when that option is selected. All I get is a flat bar graph with no
activity. The switch where it is plugged in shows a link light. The scanner
itself emits a very faint clicking sound from the inside. I know there is
loads of traffic on the line being tested. The scanner has the original
battery and I am wondering if it just doesn't have enough power to run this
test. All the other tests run fine though. It has been flashed to the latest
update too.

Am I doing something wrong?

Todd

 
 
 

Pentascanner, analyze lan traffic

Post by Bob Retell » Fri, 13 Jul 2001 15:40:49


On Wed, 11 Jul 2001 11:48:53 -0400, "Todd Felmly"


>I have an original Pentascanner. It doesn't seem to want to analyze LAN
>traffic when that option is selected. All I get is a flat bar graph with no
>activity. The switch where it is plugged in shows a link light. The scanner
>itself emits a very faint clicking sound from the inside. I know there is
>loads of traffic on the line being tested. The scanner has the original
>battery and I am wondering if it just doesn't have enough power to run this
>test. All the other tests run fine though. It has been flashed to the latest
>update too.

>Am I doing something wrong?

>Todd

Sounds to me like the Pentascanner is working OK.

The clicking is an audio indication of the LAN activity, and the graph
is a visual indication.

Apparently the "loads of traffic" on that wire is so close to zero
that it's simply drawing a flat line.

When there IS a lot of traffic, the scanner will start buzzing like a
geiger counter next to Three Mile Island, and the graph will look like
a "dot com" startup about a year ago.

Another thing-  if you're plugged into a switch, you may be getting a
skewed look at the actual LAN traffic, depending on where you';re
plugged in and how long it's been since you plugged in.

A better place to connect might be a hub that doesn't "filter" the
traffic at all, or something on the LAN "backbone" so you get ALL the
traffic.

Right now it sounds like you're only getting a few packets, probably
whatever the switch is passing through to the port you're plugged
into.

BobR

 
 
 

Pentascanner, analyze lan traffic

Post by Phil Partridg » Fri, 13 Jul 2001 06:59:20




Quote:>I have an original Pentascanner. It doesn't seem to want to analyze LAN
>traffic when that option is selected. All I get is a flat bar graph with no
>activity. The switch where it is plugged in shows a link light. The scanner
>itself emits a very faint clicking sound from the inside. I know there is
>loads of traffic on the line being tested. The scanner has the original
>battery and I am wondering if it just doesn't have enough power to run this
>test. All the other tests run fine though. It has been flashed to the latest
>update too.

>Am I doing something wrong?

>Todd

Just guessing.. But you say a 'switch' port.
Switches learn MAC addresses and 'switch' data packets to their
destination having learnt where things are on a network.
(Yes, I know about other layer switches, but lets keep it simple).
So... unless you put a hub in with at least one device on it, you won't
see much activity.
This supposes the device is working.
--
Phil Partridge
 
 
 

Pentascanner, analyze lan traffic

Post by slaphea » Sat, 14 Jul 2001 18:44:42




>On Wed, 11 Jul 2001 11:48:53 -0400, "Todd Felmly"

>>I have an original Pentascanner. It doesn't seem to want to analyze LAN
>>traffic when that option is selected. All I get is a flat bar graph with no
>>activity. The switch where it is plugged in shows a link light.
.....

>Another thing-  if you're plugged into a switch, you may be getting a
>skewed look at the actual LAN traffic, depending on where you';re
>plugged in and how long it's been since you plugged in.

The view from a standard switch port will be more than skewed!  It will
be very dark!  As others have pointed out, switches direct individual
Ethernet packets ONLY to the port(s) that should receive them.  That's
the whole purpose of using switches instead of hubs.  All you should
expect to see on an empty switch port is broadcast packets, not normal
traffic.

Some (more expensive) switches have an internal feature which can copy
all the traffic on one or more ports to a diagnostic port, or one
reassigned as such.
--
slaphead

 
 
 

Pentascanner, analyze lan traffic

Post by Mark Johnst » Wed, 25 Jul 2001 07:57:44


The preceding posts regarding switch vs hub traffic answer the
question.  Another consideration is the Penta was designed in 1993,
before 100Base-T was envisioned, and is not compatible with 100Base-T
systems.  The results when LAN monitoring 10Base-T will be fine, but
will likely show far higher utilization than is actually there when
monitoring 100Base-T.

In future, I would recommend anyone with Microtest product or cable
troubleshooting questions in general to email directly to


We have a good group of folks who are ready and willing to help.

Mark Johnston
Sr. Director of Technology Development
Microtest


> I have an original Pentascanner. It doesn't seem to want to analyze LAN
> traffic when that option is selected. All I get is a flat bar graph with no
> activity. The switch where it is plugged in shows a link light. The scanner
> itself emits a very faint clicking sound from the inside. I know there is
> loads of traffic on the line being tested. The scanner has the original
> battery and I am wondering if it just doesn't have enough power to run this
> test. All the other tests run fine though. It has been flashed to the latest
> update too.

> Am I doing something wrong?

> Todd

 
 
 

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