On Oct 21, 2010, at 4:33 AM, Ray Soucy wrote: > For for all intents and purposes if you're looking for RFC1918 style > space in IPv6 you should consider the block FD00::/8 not FC00::/7 as > the FC00::/8 space is reserved in ULA for assignment by a central > authority (who knows why, but with that much address space nobody > really cares). > > People may throw a fit at this, but as far as I'm concerned FD00::/8 > will never leave the edge of our network (we null route ULA space > before it can leak out, just like you would with RFC1918 space). So > you can pretty much use it has you see fit. If you want to keep your > ULA space short there is nothing stopping you from using something > like FD00::1 as a valid address. > I have no problem with that. My concern is that people will use FD00::/8 space in OTHER ways, and, since it has potential uniqueness if you follow the RFC, it has greater potential for undesired success than RFC-1918.
> You could embed your ASN into it or some other identifier if you want > to avoid conflicts with other non-routed address space which should > never enter or leave your network from the outside, but I'm just not > seeing the practical application for this. > That only avoids conflicts if everyone within the networks to which you may communicate uses the same system of uniqueness. Think beyond today to the future possibility of M&A of other companies also using ULA, etc. Owen > On Wed, Oct 20, 2010 at 5:48 PM, Jeroen van Aart <jer...@mompl.net> wrote: >> <IPv6 newbie> >> >> According to http://en.wikipedia.org/wiki/IPv6_address#Special_addresses an >> fc00::/7 address includes a 40-bit pseudo random number: >> >> "fc00::/7 — Unique local addresses (ULA's) are intended for local >> communication. They are routable only within a set of cooperating sites >> (analogous to the private address ranges 10/8, 172.16/12, and 192.168/16 of >> IPv4).[12] The addresses include a 40-bit pseudorandom number in the routing >> prefix intended to minimize the risk of conflicts if sites merge or packets >> are misrouted into the Internet. Despite the restricted, local usage of >> these addresses, their address scope is global, i.e. they are expected to be >> globally unique." >> >> I am trying to set up a local IPv6 network and am curious why all the >> examples I come accross do not seem to use the 40-bit pseudorandom number? >> What should I do? Use something like fd00::1234, or incorporate something >> like the interface's MAC address into the address? It'd make the address >> quite unreadable though. >> >> Thanks, >> Jeroen >> >> -- >> http://goldmark.org/jeff/stupid-disclaimers/ >> http://linuxmafia.com/~rick/faq/plural-of-virus.html >> >> > > > > -- > Ray Soucy > > Epic Communications Specialist > > Phone: +1 (207) 561-3526 > > Networkmaine, a Unit of the University of Maine System > http://www.networkmaine.net/
