Wireshark mailing list archives
Re: Nettl HP-UX
From: Guy Harris <guy () alum mit edu>
Date: Tue, 28 Jun 2011 14:46:34 -0700
On Jun 28, 2011, at 1:57 PM, Chris Maynard wrote:
Guy Harris <guy@...> writes:maxValidFrame is 1500. (And, yes, this means that values of the length/typefield between 1501 and 1535are, apparently, illegal.)So how should Wireshark handle such invalid frames?
Good question.
As a simple test, I manually modified an IEEE 802.3 Ethernet packet and changed its length from 38 bytes (with 8 bytes of trailer) to 1501 bytes. Wireshark displayed it as an Ethernet II frame of "Type: unknown (0x05dd)" and payload of 46 bytes.
Yes, the code currently treats all type/length field values < IEEE_802_3_MAX_LEN=1500 as type field values.
But if 1501-1535 are invalid, maybe at the very least an Expert Info should be added to report it?
Yes. My copy of version 1 of the DEC/Intel/Xerox Ethernet spec doesn't say anything about valid type field values, unless I missed it. Perhaps version 2 does; in any case, perhaps we should dissect frames with type/length fields in that range as invalid rather than as having a type *or* length field. ___________________________________________________________________________ Sent via: Wireshark-users mailing list <wireshark-users () wireshark org> Archives: http://www.wireshark.org/lists/wireshark-users Unsubscribe: https://wireshark.org/mailman/options/wireshark-users mailto:wireshark-users-request () wireshark org?subject=unsubscribe
Current thread:
- Re: Nettl HP-UX, (continued)
- Re: Nettl HP-UX Guy Harris (Jun 14)
- Message not available
- Re: Nettl HP-UX Guy Harris (Jun 17)
- Re: Nettl HP-UX Andrej van der Zee (Jun 19)
- Re: Nettl HP-UX Guy Harris (Jun 19)
- Re: Nettl HP-UX Guy Harris (Jun 19)
- Re: Nettl HP-UX Andrej van der Zee (Jun 19)
- Re: Nettl HP-UX Andrej van der Zee (Jun 19)
- Re: Nettl HP-UX Guy Harris (Jun 19)
- Re: Nettl HP-UX Andrej van der Zee (Jun 20)
- Re: Nettl HP-UX Chris Maynard (Jun 28)
- Re: Nettl HP-UX Guy Harris (Jun 28)
- Re: Nettl HP-UX Chris Maynard (Jun 29)
- Re: Nettl HP-UX Guy Harris (Jun 29)
- Re: Nettl HP-UX Chris Maynard (Jun 29)
- Re: Nettl HP-UX Kevin Cullimore (Jun 28)
- Re: Nettl HP-UX Chris Maynard (Jun 29)