> But, with the expanded space, there is an issue of how to transition > to the larger numbers. This is a software problem as much as > anything. Indeed, there is a software issue here which does not seem to have been carefully considered. >Until all software understands the bigger numbers, people > will want to continue using the 16-bit ones. The IESG message talked about numbers from 65536 to some big number. Here suddenly, we see a reference to some number of bits. > Meanwhile, to encourage the migration to 4-byte ASNs, the RIRs have Now there is a reference to some number of bytes. What is going on here? Is this a question of moving the maximum number from 65535 to something much larger or is it a matter of creating new notation to reflect the details of the BGP protocol change? Some people have been pushing to make the internal details of the BGP protocol externally visible even though the new ASNs are defined in such a way that any 32-bit numbers which happen to be equal to a 16-bit number are treated as if they were the old 16-bit number. In other words, if you were allocated 64999 as a 16-bit ASN, you have the right to use 64999 as a 32-bit ASN. Because of this, some people are demanding that a new notation be developed to place a punctuation character, either a dot or a colon, between the two 16-bit segments or between the 2nd and the 3rd byte, if you want to count bytes. Using this system, there can be no such thing as AS 65536 as was stated in the IESG message. Instead, that 32 bit quantity will be referred to as 1.0 or 1:0. On the NANOG list it has already been pointed out that a lot of network management software cannot handle such notation and in some cases, 1.0 could be interpreted as the IP address 1.0.0.0. It has been confirmed that one widely used PERL library interprets x.y as IP address x.0.0.y. Because of this I think it would be useful for the IETF to publish a draft defining the notation for AS numbers so that we can either keep it simple or, if a new notation is to be used, then publicly state the issues of software which needs to be changed. Such a draft should really come from the WG which extended the AS number in the first place. --Michael Dillon _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf