RFC: Partial IP4 syntax

Ben Efros ben at xgendev.com
Wed Sep 29 05:56:19 CEST 2004


Simon Lodal wrote:

> Examples:
> 10 = 10.0.0.0/8

<SNIP>

> Iknow IP address syntax should not change every day. But this will not 
> break or exclude old syntax. I do not see it clashing with 
> other/future syntax.

Wrong.  IP numbers can also be written in 32-bit unsigned notation.  In 
your first example:
10 being  10.0.0.0/8
10 is actually treated as unsigned 32bit int, meaning you're address is 
actually 0.0.0.10
Try this command and see for yourself:
"ping 5000"
Notice how ping is actually sending to "0.0.19.136" ?

This is done because 32-bit addresses should be representable as a 32bit 
number and not just as a string representation of the address for a 
variety of reasons.

Unfortunately your idea would break a LOT of very useful tools and ways 
of representing valid ip numbers.

Ben



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