On Fri, 2002-11-22 at 09:34, Markku Savela wrote: > > > Fine by me. It's just that dealing with scopes seems to be the problem that > > most people are complaining about rather than the existence of the addresses > > themselves. > > I cannot understand those people complaining about scopes. We will > have > > (a) addresses that are global > (b) addresses that are local, with limited reach (firewalled or > whatever)
I'd take a step back (up?) to a higher level and say there are only really three fundamental scopes : 1) External 2) Internal 3) Link local Reliable External communications requires globally unique addressing. Reliable Internal communications does not require globally unique addressing, but does require internally unique addressing. The current site-local model seems to me to be a too restrictive solution to the Internal communications requirement, as it creates artificial boundaries on the definition of Internal communications. Further, with the current site-local model, you have to assume that there will be addressing collisions when merging even the smallest of two "sites" - there is a fairly good chance that most people will use fec0:0:0:1::/64 for their first subnet. This duplicated address space, and almost guaranteed chance of address space collision seems to me to be the cause of a lot of the recent arguments about site-local addressing, including problems cross site address referrals etc, and solutions such as multi-site routers etc that just feel to be way to complex to me. Pekka's solution reverses that assumption. In the majority of cases, you won't have a duplicated (on a global scale) Internal address space, making merging "sites" a simple as bringing up the link between the sites, and pushing a few routes between the networks. On the rare occasions that there is a Internal address space collision under Pekka's model, it will (or at least should) be discovered during the preparation for the connection of the two "sites" together. In the case of a collision, having to renumber one of the Internal address spaces to make it unique again is unfortunate, but it is the price of requiring an Internal address space that is independent of your provider supplied global address space. Regards, Mark. -------------------------------------------------------------------- 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] --------------------------------------------------------------------
