Le 2012-01-06 à 07:48, Fernando Gont a écrit : > Hi, Rémi, > > On 01/05/2012 02:02 PM, Rémi Després wrote: >> Hi Fernando, >> >> Full agreement on the substance of your draft, and support for an RFC based >> on it. >> >> However, I believe it should rather be a BCP than a Standard-track RFC. >> (I don't see any need to standardize anything beyond what already exists.) > > How is this different from, e.g. standardizing that hosts should discard > overlapping fragments on Std Track?
Discarding receiving fragments that overlap (RFC is IMHO something that might ALSO have been treated as BCP: it doesn't change the protocol. (Implementations that don't comply with the new provision still interwork with those that do.) An ambiguity however exists in RFC 2460 because it describes a specific reassembly algorithm without saying it isn't part of the standard. This algorithm, which could have been left to implementors to choose based on how sources do fragmentation, doesn't include the consistency check that fragments don't overlap. It it then worth specifying that the described algorithm isn't as complete as it could be. I have to agree that the logic of what you propose, although less important IMHO, is similar. Therefore, and despite my comment, I don't really care whether it ends up as a standard rather than a BCP if others so prefer. Regards, RD > > Thanks, > -- > Fernando Gont > SI6 Networks > e-mail: [email protected] > PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492 > > > Sec 4.5 The following conditions are not expected to occur, but are not considered errors if they do: The number and content of the headers preceding the Fragment header of different fragments of the same original packet may differ. Whatever headers are present, preceding the Fragment header in each fragment packet, are processed when the packets arrive, prior to queueing the fragments for reassembly. Only those headers in the Offset zero fragment packet are retained in the reassembled packet. The Next Header values in the Fragment headers of different fragments of the same original packet may differ. Only the value from the Offset zero fragment packet is used for reassembly. -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
