North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: v6 subnet size for DSL & leased line customers
-- On Sun, 12/23/07, Chris Adams <[email protected]> wrote: > From: Chris Adams <[email protected]> > Subject: Re: v6 subnet size for DSL & leased line customers > To: [email protected] > Date: Sunday, December 23, 2007, 2:21 PM > Once upon a time, Florian Weimer <[email protected]> > said: > > >> Right now, we might say "wow, 256 > subnets for a single end-user... > > >> hogwash!" and in years to come, > "wow, only 256 subnets... what were we > > >> thinking!?" > > > > > > Well, what's the likelihood of the "only > 256 subnets" problem? > > > > There's a tendency to move away from (simulated) > shared media networks. > > "One host per subnet" might become the norm. > > So each host will end up with a /64? > > How exactly are end-users expected to manage this? Having > a subnet for > the kitchen appliances and a subnet for the home theater, > both of which > can talk to the subnet for the home computer(s), but not to > each other, > will be far beyond the abilities of the average home user. As I see it, one of the big benefits IPv4 provided was logical addresssing in an easy-to-understand and easy-to-aggregate manner, with small layer-2 networks divided by routers. What we've gone to with IPv6 is a gigantic layer-2 network (the flat autoconfiguration space). I think we got here when "site-local" went away - we've effectively redefined link-local to mean "site-local," while using globally unique addressing. Personally, I don't relish the idea of millions of hosts participating in spanning-tree, so I'd rather see us move back toward the direction of using layer-3 addresses to break up layer-2 islands. How about this for a modest proposal for a capability: Allow autoconfigured generation of IPv6 interface addresses to use this format: (one byte VLAN ID) (48 bit MAC address) instead of: (24 bit half-mac) (FFFE) (24 bit half-MAC) This would allow a CPE router to serve as the gateway for up to 64K VLANs, and wouldn't waste a byte in the middle of the address space. How about it? David Barak Need Geek Rock? Try The Franchise: http://www.listentothefranchise.com ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
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