Sniffing Set top boxes

[reborn]

Hi all,

I'am trying to sniff the traffic of set top box which is connected to local 5 port netgear switch,
all i can see is udp streams and ssdp requests and that too from different ip address which is not reachable if i try to ping / nmap
also Set top box ip address is like 192.168.x.x and from that i can only see ssdp requests and none other evident traffic like
authentication/any other port -ip connection /protocols etc
so the question arises here is , am i doing it right ? or i need to do something like port forwarding or port mirroring ?
i won't be able to do such thing i think because the switch doesnt have any such interface of changing configurations i guess.
any suggestions or advice will be very helpful.

thanks !

[Geek-9pm]

Why do you want to do that?
What tools are you musing?
 Either hardware or software?

This was popular a few years back.
http://www.pcmag.com/article2/0,2817,2348279,00.asp
Cisco Network Magic Pro 5.5

Excellent tool for learning about your home network. Easy way to share folders and printers. Displays a visual map of your network in real time.

But even the above report goes on to  say it has limits.

[reborn]

I'm using just wireshark to know what traffic is passing other than ssdp and udp streams, but it seems it only captures passively.
and i'm doing this to analyse STB traffic / information it sends across the network.

[camerongray]

Your switch will be routing most of the traffic directly to the correct port (such as the one going out to the internet) so the PC doing the sniffing won't see many of the packets from the STB.  Therefore you would need something like port mirroring however this of course requires a switch that supports it.  A couple of cheaper options would be to connect the STB directly into your PC and use it to provide an internet connection to the box such as through Windows's internet connection sharing.  You could also pick up a cheap, used *hub* as this will blindly forward packets to all ports allowing you to sniff them (much like you get with a switch with port mirroring).

[reborn]

thanks cameron,
that was quite informative from you, so now another question is .. can i setup a server which STB communicates directly to on my machine?
if yes does anyone has such information on kind of server that has to be setup?