On 09/11/14 13:11, William Waites wrote:
> Operationally, what does this mean? The most common case is going to
> be a single subnet, so how is the gateway going to know which one out
> of the /56 to use? Somebody has to pick a /64 to put on the inside
> ethernet interface. How is this done? No problem *assigning* a /56 but
> using it is another matter.

Hi,

I've seen all sorts of tricks being made on this topic...

Some of them assign /56 to residential customer and:

- use wan interfaces unnunmbered (just link-local addreses and installed
route on BRAS towards wan ll interface)

-or-

- use the first /64 for ppp/wan link and the rest for LAN

-or-

- assign separate /64 for wan link and separate /56 for LAN side.

/56 on the LAN side gets auto-configured as on well behaved CPEs there
is a script for that. Usually, one address (from first /64) is assigned
to local loopback and next /64 is put on first L3 port and next one on
next L3 port and so on... you can of course change the ID of where the
/64 assignments starts.

http://wiki.openwrt.org/doc/uci/network6#downstream.configuration.for.lan-interfaces
(an example).

Cheers, Jan