Ethereal-users: [Ethereal-users] ARP and Ethernet_II trailer display

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

Date Prev · Date Next · Thread Prev · Thread Next
From: Cameron Kerr <cameron.kerr@xxxxxxxxxxxxxxx>
Date: Wed, 02 May 2001 01:03:13 +1200
(Note to self: If netscape crashes when sending mail again, throttle the
dang thing)

Hi, sorry if the third in you inbox (this is just getting silly).

I have been making a toy ethernet sniffer/decoder, and its having
trouble on ARP packets, so I decided to compare my results with
Ethereal, as I often had been doing.

I noticed that when Ethereal displays an ARP packet, if the opcode
of the ARP packet is REPLY, then in the Ethernet_II breakdown,
it will show the Trailer field (padding, as I understand it, to
meet the minimum requirement of Ethernet_II data size).

However, when the packet is ARP REQUEST, it does not show this
packet! Why? Is it some oversight/error or is there not supposed
to be any data there?

PS. Then reading frames in using PF_PACKET and SOCK_RAW, does
the data have any padding stripped off?

Thanks. All input appreciated.

PPS. Please cc replies to my email, since I am not a member of
this group. Thanks.

(Now remember to save, BEFORE you send...)
-- 
Cameron Kerr -- cameron.kerr @ paradise.net.nz
Praise Slackware, our baud and saviour!
--