Wireshark-users: Re: [Wireshark-users] Capture the time where no troughput is present

From: Ian Schorr <ian.schorr@xxxxxxxxx>
Date: Fri, 10 Jul 2009 10:16:10 +1000
No, it does two separate things.  It gives you stats for all packets, and then displays all packets that match the filter "ftp".

If you want the stats themselves to match a filter, you'd do something like:
tshark -r <file> -z io,stat,1,ftp <--- note the comma - this "ftp" applies a filter to the stats generation.  Without a comma you're telling tshark what filter it applies to packets it should *display*.

Careful on using "ftp" filter here, too.  The "ftp" filter is going to match any packet that is decoded as FTP protocol - just the management packets.  The actual file transfer, on the data channel, will either be decoded as "ftp-data" or (I believe in some cases) just simply as "tcp".  Using a filter like "tcp.port==20 or tcp.port==21" might give you the stats you're looking for more reliably.

I forgot to mention that if you don't want tshark to actually display any packets (just the stats table), you'll want to feed it a "display filter" that matches no packets.  So you could do something like:

tshark -r <file> -R "not frame" -z io,stat,1,"tcp.port==20 or tcp.port==21"  (every packet matches the filter "frame" so a display filter of "not frame" basically says "display any packets")


On Thu, Jul 9, 2009 at 9:20 PM, Lutti Hautameki <bowkatz@xxxxxxxxx> wrote:
Hello Ian,
I've got a question to you:
 
when i issue this command : tshark -r C:\test2.pcap -z io,stat,1 ftp
 
it just shows the io graph of ftp packets or ?