On Sep 22, 2003, at 10:35 AM, Darren Forster wrote:
I get capture files from various devices and have produced a simple
java gui
to import the captured frames into ethereal.
I can get Cisco HDLC, PPP and raw IP into ethereal using the listed
data
link values in libpcap but I would like to know the data link values
for
mtp2 and lapd - q931.
You can't, because there aren't any.
There's some work in progress to handle MTP2, but I infer that Jeff
Morriss will be changing the way we handle MTP2/MTP3/whatever that
Swhatever protocol was to remove an apparently-unnecessary length
field; once that's done, you'd be able to use that.
Nobody's created one for LAPD - or, perhaps more appropriately, for
ISDN, with a pseudo-header giving the channel number.
(ideally I could do with a list of all data link values that I can use
to
force decoding of layer 2 protocols).
The list of data link values *is* the one in libpcap. If it's not
there, you can't use it in Ethereal. If you need one for Ethereal, it
needs to be added to libpcap; ask tcpdump-workers@xxxxxxxxxxx for one
(and give a detailed description of the way the packets will be
encapsulated).
