Hi Andrew, On Wed, 2003-08-06 at 13:20, Andrew White wrote: > Particularly focusing on the FD00/8 space... > > I'll raise my sole dissention up front: > > 3.2.2 and 3.2.3 are unnecessarily prescriptive for local addresses. Since > the goal is simply to get something which is 'good enough' unique, all you > need is a mechanism for choosing a number that no-one else is likely to be > using. > > For /48, hashing from an EUI-48 is currently good enough, although you are > compressing 48 bits into 40 so it could possibly cause problems when the > EUI-48 space is saturated. >
As I see it, the problem is not so much that a hash of UI-48s wouldn't be adequate for this purpose, the issue is that net admins / end users would want to know which one of their 10, 100, 1000 or 10 000 etc. EUI-48s in their network is best to use for this purpose. Obviously it doesn't matter, but providing an explicit procedure to generate the 'good enough' unique number that doesn't depend on one of the EUI-48 values embedded in a device, will eliminate questions about which is the best EUI-48 address to use from IPv6 mailing lists / discussion forums, support lines etc, and possibly this mail list, even when there is no best EUI-48 to use. It also prevents people from making up an EUI-48 when they don't know how to find out an EUI-48 from one of their devices. In that case, the range of selected EUI-48s will become very predictable - I'd suggest we would encounter a number of 00:00:00:00:00:00s, 11:11:11:11:11:11s, and 00:00:00:00:00:01s, in addition to the various, novel hexisms that exist, such as my favorite, "ba:db:ad:c0:ff:ee" Regards, Mark. > -- > Andrew White > -------------------------------------------------------------------- > IETF IPng Working Group Mailing List > IPng Home Page: http://playground.sun.com/ipng > FTP archive: ftp://playground.sun.com/pub/ipng > Direct all administrative requests to [EMAIL PROTECTED] > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPng Working Group Mailing List IPng Home Page: http://playground.sun.com/ipng FTP archive: ftp://playground.sun.com/pub/ipng Direct all administrative requests to [EMAIL PROTECTED] --------------------------------------------------------------------
