Re: IPv6 minimum Link MTU

I am not positive on that, but I believe it has to do with efficiency. That
is, an efficient header:data ratio that the designers felt was the most
optimized. Also keep in mind that IPv6 routers do NOT do fragmentation : )
In IPv6, the source host must do fragmentation based on the lowest MTU along
the path.

On Thu, Aug 27, 2009 at 2:42 AM, Anantha Subramanian Natarajan <
anantha.natarajan_at_gravitant.com> wrote:

> Hi Joe,
>
> Got it and thanks for addressing the answer referring to the RFC for
> IPv4.What about IPv6,is it on similiar lines.( I think,the basic header of
> ipv6 is 40 octets and it has options for extension headers,so adding both
> may come to close around 1280 octets ?)
>
> Thank You
>
> Regards
> Anantha Subramanian Natarajan
>
>
>
> On Thu, Aug 27, 2009 at 1:29 AM, Joe Astorino <jastorino_at_ipexpert.com>wrote:
>
>> To answer your question about IPv4, from RFC791 (IP)
>>
>> "Every internet module must be able to forward a datagram of 68
>>
>> octets without further fragmentation. This is because an internet
>>
>> header may be up to 60 octets, and the minimum fragment is 8 octets.
>>
>> Every internet destination must be able to receive a datagram of 576
>> octets either in one piece or in fragments to be reassembled."
>>
>>
>> On Thu, Aug 27, 2009 at 2:04 AM, Anantha Subramanian Natarajan <
>> anantha.natarajan_at_gravitant.com> wrote:
>>
>>> Hi All,
>>>
>>> When I was going through the Doc CD for IPv6,I read about the "Minimum
>>> Link MTU is 1280 octets in IPv6".Even when referred the RFC 2460 (IPv6
>>> specification),it highlights the same.I am just curious about the
>>> significance of that number "1280 octets".How that is derived ?.Even I
>>> didn't know,what is the significance of the number 68 octets,which is
>>> minimum MTU size for Ipv4 .
>>>
>>> Any clarification is really appreciated.
>>>
>>> Thanks for the help
>>>
>>> Regards
>>> Anantha Subramanian Natarajan
>>>
>>>
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>>
>>
>> --
>> Regards,
>>
>> Joe Astorino - CCIE #24347 R&S
>> Technical Instructor - IPexpert, Inc.
>> Cell: +1.586.212.6107
>> Fax: +1.810.454.0130
>> Mailto: jastorino_at_ipexpert.com
>>
>
>

-- 
Regards,
Joe Astorino - CCIE #24347 R&S
Technical Instructor - IPexpert, Inc.
Cell: +1.586.212.6107
Fax: +1.810.454.0130
Mailto:  jastorino_at_ipexpert.com
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