That's an example of the lack of plain English in the proposal. Why don't we just talk about AS numbers greater than 65535 or AS numbers less than 65536?
Because there is more to it than just that. :)
there is the matter of whether they are represented by 2 bytes, or 4 bytes _in_transmission_. '0x00004F4F' is a '4-byte' AS number that has a value less than 65,536. It _should_ be treated identically with the 2-byte AS
number '0x4F4F',
Thank you for pointing out why we don't need to concern ourselves with the difference between old AS 2 and new AS 2. They are the same in every way that matters except to protocol sniffers and protocol implementors. The new AS number spec says so itself.
Is it? <grin>
Do you represent AS 17 in two bytes, or four?
if you use 2 bytes, do you, "somewhere down the road", change to representing it with 4 bytes? or do you deal with 'mixed-length' codes "in
Right now I am representing it in 4 bytes because by email client uses two bytes (UTF8) per decimal digit. But what difference does this make. Whether it is 17, 021, 0x11 or "17" it is still greater than 16 and less than 18. perpetuity"? The whole discussion on PPML is about ARIN beginning to use 4 byte binary representation for AS numbers so that they can begin giving out AS numbers greater than 65535 to those people who *WANT* such numbers in order to use 4 byte AS numbers operationally. And to be ready for the day when AS numbers less than 65536 have run out. It is a good idea for people to begin scheduling this change in any internal systems which record AS numbers in binary form. Of course, those far-sighted companies who represent AS numbers as variable length strings in their applications and databases will have no need to change things. If you had to cross-post from PPML, you could have chosen something with more operational relevance like the fact that multiple networks will appear to be using AS 23456 because at the boundary between old BGP4 speakers and new BGP4 speakers, any AS numbers greater than 65535 will be mapped into AS 23456. --Michael Dillon