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Re: mech-v2-05pre
Vlad,
Pekka has already provided I think a good rationale for the version check,
and it is beyond the scope of this document to say what decapsulators
do when encapsulated packets with version other than '6' are received.
Fred L.Templin
Wouldn't the version check be part of the standard IPv6 processing?
Why do we want to mandate it here as well?
I can see the need to make sure that we have enough data, so the
decapsulator may want to check that it has at least 40 bytes of
payload, but the version check seems redundant to me.
-vlad
Pekka Savola wrote:
> On Wed, 25 Aug 2004, Fred Templin wrote:
>
>>In section 3.6, change:
>>
>> "If the payload is not at least 40 bytes in length (i.e., the minimum
>> IPv6 packet), the packet MUST be discarded. Likewise, if the the
>> version encoded in the first 4 bits of the encapsulated packet is not
>> "6", the packet MUST be discarded.
>>
>> The encapsulating IPv4 header is discarded."
>>
>>to:
>>
>> "The encapsulating IPv4
header is discarded, and the version
>> encoded in the first 4 bits of encapsulated packet is checked.
>> If the version is "6" and the payload is not at least 40 bytes in
>> length (i.e., the minimum IPv6 packet), the packet is discarded.
>> (Procedures for handling packets with version other than "6" are
>> out of scope.)"
>>
>>If anyone is unsure why this is being suggested, please see the
>>IPvLX draft before commenting here.
>
>
> I think this proposed change would only add ambiguity. It seems
> clearer to specify these before specifying discarding the v4 header.
>
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Vladislav Yasevich Linux and Open Source Lab
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