Re: Echo request and echo reply

It is Google specific. They do a lot of "optimizations" to save on
bandwidth. Just run an HTML validator against their site:

http://validator.w3.org/check?verbose=1&uri=http://www.google.com/

Additionally if you look at the HTML source of www.google.com you'll
notice that they don't include </body> or </html>. The amount of
bandwidth saved is really amazing for small things like this when you're
working on the scale of Google's networks.

Brian Dennis, CCIEx5 #2210 (R&S/ISP-Dial/Security/SP/Voice)
bdennis_at_ine.com

Internetwork Expert, Inc.
http://www.INE.com

On 11/1/11 7:20 AM, "Piotr Matusiak" <pitt2k_at_gmail.com> wrote:

>It seems to be Google specific in this case as when I ping cisco.com it
>replies with the same size :)
>
>Regards,
>--
>Piotr Matusiak
>CCIE #19860 (R&S, Security), CCSI #33705
>Technical Instructor
>website: www.MicronicsTraining.com <http://www.micronicstraining.com/>
>blog: www.ccie1.com
>
>If you can't explain it simply, you don't understand it well enough -
>Albert Einstein
>
>
>2011/11/1 Carlos G Mendioroz <tron_at_huapi.ba.ar>
>
>> Hmm,
>> The question was specific to 8.8.8.8, which is a specific host (or set
>>of
>> hosts :) that actually DO NOT behave like RFC-792 asks.
>>
>> FTR, RFC-792 says:
>>
>> Data received in an ICMP Echo Request MUST be entirely included in the
>> resulting Echo Reply. However, if sending the Echo Reply requires
>> intentional fragmentation that is not implemented, the datagram MUST
>> be truncated to maximum transmission size (see Section 3.3.3) and
>> sent.
>> ...
>>
>> If a Record Route and/or Time Stamp option is received in an ICMP Echo
>> Request, this option (these options) SHOULD be updated to include the
>> current host and included in the IP header of the Echo Reply message,
>> without "truncation". Thus, the recorded route will be for the entire
>> round trip.
>>
>> but testing shows that 8.8.8.8 answers with small reply when data size
>> gets over 64 bytes.
>>
>> -Carlos
>>
>> Piotr Matusiak @ 01/11/2011 10:00 -0300 dixit:
>>
>>> Yes
>>>
>>> Regards,
>>> --
>>> Piotr Matusiak
>>> CCIE #19860 (R&S, Security), CCSI #33705
>>> Technical Instructor
>>> website: www.MicronicsTraining.com <http://www.micronicstraining.com/>
>>><
>>> http://www.micronicstraining.**com/
>>><http://www.micronicstraining.com/>>
>>>
>>> blog: www.ccie1.com
>>>
>>> If you can't explain it simply, you don't understand it well enough -
>>> Albert Einstein
>>>
>>>
>>> 2011/11/1 amin <amin_at_axizo.com>
>>>
>>> Hi experts,
>>>>
>>>>
>>>>
>>>> If I do extended ping 8.8.8.8 size 2000, this is the size of the echo
>>>> request, what will be the size of the echo replay? It will be the same
>>>> size??
>>>>
>>>>
>>>>
>>>> Regards,
>>>>
>>>> Amin
>>>>
>>>>
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>>>
>> --
>> Carlos G Mendioroz <tron_at_huapi.ba.ar> LW7 EQI Argentina
>
>
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Received on Tue Nov 01 2011 - 12:27:07 ART