quick network engineering review question

[Kelsay, Brian - Kansas City, MO]

If the cable you normally have is a crossover, it should be marked as
such.  Did you make it yourself in days gone by?  Sometimes they are
printed on the cable "crossover" or they have a special colored band on
each end near the connector.  You can also put the two ends together and
compare the wire color order (the end should be clear).  If they are in
the same order, then it is normal (straight thru, if several seem mixed
up, then it is a crossover.

I don't see why your setup with the hub or switch wouldn't work.
Probably a hub is better since all ports receive the same messages.
Then you need to put a PC with Linux in there on the hub, with at least
one network card in promiscuous mode.  Google that and you will find out
how to do it.  There are then several tools that you can use to sniff.
Snort, ethereal, snarf, etc., Google TCP/IP traffic sniffing.

One thing I just thought of.  The packets coming in to the router may be
in chunks like frames.  Your standard PC NIC may not be able to decode
them.  I reserve the right to be wrong and admit it in an open forum.
You have some research ahead of you anyway.

>-----Original Message-----
>From: kclug-bounces at kclug.org [mailto:kclug-bounces at kclug.org] 
>On Behalf Of crash3m
>Sent: Thursday, June 02, 2005 1:06 PM
>To: kclug at kclug.org
>Subject: Re: quick network engineering review question
>
>
>Maybe if you explained why you need to sniff the traffic someone could
>offer a solution.  Maybe your answer can be solved by sniffing on the
>'internal' side of the CSU/DSU.
>
>On 6/1/05, David Nicol <davidnicol at gmail.com> wrote:
>> I want to sniff all traffic on the upstream link at my 
>installation.  I have a
>> wire that comes into my Cisco router from the CSU/DSU.  The 
>question is,
>> is this wire a normal Ethernet wire, so that I could plug it 
>into a hub and plug
>> the hub into the Cisco, that is, put a hub in line with it, 
>or is it something
>> else?
>> 
>> I already have the crossover cable for the new connection, 
>if plugging the
>> CSU/DSU wire into a hub is in fact copasetic.
>> 
>> Please reply on or off list as appropriate
>> 
>> 
>> --
>> David L Nicol
>> Twinkies and Wonderbread are mainstream Americana