Date: Tue, 02 Jun 1998 08:17:38 -0400 From: "Louis A. Mamakos" <louie@TransSys.COM> To: Chrisy Luke <chrisy@flix.net> Cc: Philippe Regnauld <regnauld@deepo.prosa.dk>, Paul Emerson <paul@gta.com>, freebsd-net@FreeBSD.ORG Subject: Re: ipv6 network addresses Message-ID: <199806021217.IAA01494@whizzo.transsys.com> In-Reply-To: Your message of "Tue, 02 Jun 1998 11:10:02 BST." <19980602111002.31706@flix.net> References: <199806012000.QAA14487@gta.gta.com> <19980602092305.52419@flix.net> <19980602105525.36962@deepo.prosa.dk> <19980602111002.31706@flix.net>
next in thread | previous in thread | raw e-mail | index | archive | help
> However, as I understood it, IPv6 addresses will be relatively > freely available (as compared to IPv4) and so anyone that suspects they > may need to renumber sometime in the future can get them from day one, > without the requirement of being multihomed or any such. The availability of addresses has nothing to do with the likelyhood of having to renumber. Provider-based addressing is pervasive these days so that the global Internet routing table doesn't explode in size. The size of the routing table is of very much more concern than running out of address space. And it's just not the amount of memeory needed (pretty much all of the Cisco routers in the default-free part of the Internet have 64MB, mostly 128MB of memory), but the amount of processing required to handle the routing updates. Aggregating a bunch of prefixes means that external to the AS, you don't see the instability of any single network; this reduces the "churn" in the routing table which is also of concern. So, NAT is a convienience to those behind the translation, as they can change providers without having to renumber all their machines, and it enables them to easily use address space out of a provider block, which help keep the routers from exploding. There are some approaches suggested in IPv6 (the so-called 8+8 addressing scheme) which aims to address this problem; essentially, you take a part of the 16 byte address and use it as a provider/AS selector. It can be changed on the fly by routers and is not used as part of identifing the endpoint. This would allow renumbering and aliasing of addresses, which would help significantly if you were multihomed. Alas, this is not yet an intergral part of the IPv6 architecture or fielded implementations. louie To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199806021217.IAA01494>