The reason behind 576 bytes

Hi,

I find that the minimum size specified in the IP standard, 576 bytes
But, How and why did they decide to fix the mininum size to be 576
bytes. I am interested in understanding the reason behind this
decision of 576 bytes . Any links / ideas ?

Thx in advans,
Karthik Balaguru

On 03/18/08 12:40, karthikbalaguru wrote:
> Hi,
>
> I find that the minimum size specified in the IP standard, 576 bytes
> But, How and why did they decide to fix the mininum size to be 576
> bytes. I am interested in understanding the reason behind this
> decision of 576 bytes . Any links / ideas ?
>
> Thx in advans,
> Karthik Balaguru
>

If you will check out RFC 791 defining the IP protocol, example 1
in appendix A shows a complete datagram with a total length of
21 octets. Perhaps you are confusing datagram size with the minimum
size packet that a host must also be able to accept? This is also
defined in RFC 791 and came from a reasonable guess of 64 octets of
header plus 512 octets of data.

Doug

karthikbalaguru <(E-Mail Removed)> wrote:
> I find that the minimum size specified in the IP standard, 576 bytes
> But, How and why did they decide to fix the mininum size to be 576
> bytes. I am interested in understanding the reason behind this
> decision of 576 bytes . Any links / ideas ?

That is the minimum maximum IP reassembly size - that is, all
conforming implementations of IPv4 must be able to reassemble IP
datagrams at least 576 bytes in size.

As suggested by others, that differs from a minimum IP datagram size.

rick jones
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