On Wed, 20 Oct 2010 14:48:47 -0700 Jeroen van Aart <jeroen@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 a pseudo random number, not follow bad examples. Where are these examples? I'd be curious as to what they say regarding why they haven't followed the pseudo random number requirement.
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.
DNS (including dynamic DNS, multicast DNS, and DNS service discovery) is intended to be used far more often in IPv6 than it was in IPv4. It was never going to be that possible to expand the size of the address space significantly without trading off 'rememberability'. The best way to understand ULAs is to read the RFC. It'd probably take about 15 to 20 minutes, and is quite readable (as are most if not all RFCs) Unique Local IPv6 Unicast Addresses http://tools.ietf.org/rfc/rfc4193.txt You may also wish to subscribe to the ipv6-ops mailing list for IPv6 focused operations discussions. http://lists.cluenet.de/mailman/listinfo/ipv6-ops Regards, Mark.