Re: [PCTECH] Ethereal -- network protocol analyzer

["Adam Lang" <aalang@xxxxxxxxxxxxxxxxxxxx>]

Ok, you have to realize that packets don't typically go directly from point
A to point B.

If you turn your computer's network adapter on to promiscuous mode, you can
monitor packets that are meant for other computers as well.  When a NIC
isn't in promiscuos mode (normal mode) it will only "read" packets that is
intended for it.

Now, things get a little different when you have switches.  Sometimes the
switches will filter traffic and then, even in promiscuos mode, you will
only see the packets on your line and not the whole network.

----- Original Message ----- 
From: "Vern Hamberg" <vhamberg@xxxxxxxxxxxxxxxxxxxxxxxxx>
To: "PC Technical Discussion for iSeries Users" <pctech@xxxxxxxxxxxx>
Sent: Monday, March 22, 2004 8:57 AM
Subject: Re: [PCTECH] Ethereal -- network protocol analyzer


> Thanks, Adam. I assume this means (this is new to me) all traffic that
hits
> the adapter? So this would be limited to addresses with the same network
> address and subnet mask? And can switches block access to other IP
> addresses on the subnet, since they send packets selectively?
>
> My other question really was, does the parsing of packets done in a 400
> comm trace result in the same information that Ethereal presents for a
> packet? Trying to see whether we have the capability already for
> iSeries-related traffic.
>
> Just wondering.
>
> Vern
>
> At 08:40 AM 3/22/2004 -0500, you wrote:
> >No.  If your network adapter is set to promiscuous mode, you can get
packets
> >for all devices on your network.
> >
> >----- Original Message -----
> >From: "Vern Hamberg" <vhamberg@xxxxxxxxxxxxxxxxxxxxxxxxx>
> >To: "PC Technical Discussion for iSeries Users" <pctech@xxxxxxxxxxxx>
> >Sent: Monday, March 22, 2004 7:51 AM
> >Subject: Re: [PCTECH] Ethereal -- network protocol analyzer
> >
> >
> > > Hi, David, have you looked at the TCP/IP packets on an iSeries comm
trace
> > > report? It parses all the fields of the packet, as well as showing the
raw
> > > data. Granted, it would only be between the iSeries and whatever is
> > > connected to it, but that's the same for any sniffer, unless you put
one
> >at
> > > a common connection to all hosts, I suppose.
>
>
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