[ppml] 2005-1 and/or Multi6

Thomas Narten narten at us.ibm.com
Thu Apr 14 12:56:38 EDT 2005

> We have to allocate PI addresses to these so-called 
> end-sites because to do otherwise is restraint of trade.
> However, it is unwise and imprudent to offer them /48
> prefixes which are highly wasteful of global router capacity

I would like to hear from router vendors that they actually do intend
to do this sort of optimization. The reason I ask is that even if 99%
of the routes one deals with are short prefixes (e.g., /32) there will
always be a need to deal with longer ones too. E.g., for routes within
your AS, etc. So I'm not sure the above arguement actually holds water
at the end of the day.

> when we could give them shorter /32 prefixes. In doing so
> we are leveraging the vast oversupply of IPv6 address space
> to help conserve the processor, memory, and circuit capacity
> of network operators.

One reason why I would not want to give end sites a /32 in this case
is that at some point in the future, there may well be a need to
filter prefixes in order to keep the routing system working. If
everyone gets the same size (big) prefix (big ISPs with lots of
customers, and relatively small end sites that happen to be furtunate
enough to join the ASN land grab), there will be no way to filter
(sensibly) on those that do aggregate vs. those that do not. That is
not a place I'd like to be.

At some point in the future, when filtering is _required_ to keep the
routing infrastructure functioning, ISPs will want to be able to
impose filtering that makes at least some sense. Giving everyone equal
size prefixes pretty much ensures that will never happen, because they
will all look the same.


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