Hello Guy Harris Thanks for the detailed answer!
David Front CERN IT ----- Original Message ----- From: "Guy Harris" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, August 25, 2004 8:18 PM Subject: Re: [tcpdump-workers] 'tcpdump -s0' payload length limit? > > On Aug 25, 2004, at 11:09 AM, Guy Harris wrote: > > > Note, however, that the reassembly is *NOT* done at the low-layer > > capture level, so a capture filter of "port 12509" will only capture > > the first fragment of a fragmented datagram, and Ethereal and > > Tethereal will *NOT* be able to reassemble the packet. You would have > > to specify a filter that looks only at the IP headers, such as a > > filter that checks for UDP, or that checks for UDP traffic between two > > particular hosts, in order to capture *all* the fragments. > > Or you could use a filter that captures traffic to/from port 12509 *or* > that has a non-zero fragment offset, so it captures port 12509 traffic > *and* all fragments other than first/only fragments. That might > capture fragments that you don't need, but that's the best you can do. > Constructing such a filter is left as an exercise to the reader. > > Such a filter, used with tcpdump, would get the subsequent fragments; > tcpdump wouldn't reassemble them, but it'd at least print them, which > might be enough. > > - > This is the tcpdump-workers list. > Visit https://lists.sandelman.ca/ to unsubscribe. > - This is the tcpdump-workers list. Visit https://lists.sandelman.ca/ to unsubscribe.