end user assignment best practice

[Sander Steffann]

Hi Pim,

>>> Is it acceptable practice to number the "LAN" interface using a /64 taken from the /48 assigned for the customer, or is it current practice to use a second /64 outside of the /48 to route the /48 to customer equipment?  In other words, in a scenario such as this, are we to provide [/64 + /64 + /48] or [/64 + (/48 - /64)] to the end site?
>> 
>> Taking one /64 from the /48 of the end user might interfere with their addressing plan, internal aggregation etc. It really depends on the kind of customers you have, but it's something to keep in ming.
> On the other hand though, one might say that if the /48 is the
> customer's assignment, that they have to provide the transit network,
> right? Then one /48 with the /64 taken from that is acceptable IMO.

I agree that it is acceptable, the problem is often which /64 to use.  I have seen a situation where the customer made a nice addressing plan, and then the ISP took a /64 for the interconnect which didn't fit in the addressing plan at all. The customer decided to use xxxx:xxxx:xxxx:0000:/64 for the loopback interfaces of their routers, and the ISP took exactly that /64 for the interconnect. Not a disaster, but annoying for the customer. So I usually choose to use a separate /64 for the interconnect and let the customer take full management of the /48.

Cheers,
Sander